diff --git a/CMakeLists.txt b/CMakeLists.txt
index ee880c6350f..2f65549a85c 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -493,9 +493,7 @@ if (BUILD_TESTING)
         string(REGEX REPLACE ".+\\/(.+)\\.c" "\\1" test_case_name ${test_case})
 
         add_executable(${test_case_name} ${test_case})
-        target_include_directories(${test_case_name} PRIVATE api)
         target_include_directories(${test_case_name} PRIVATE ./)
-        target_include_directories(${test_case_name} PRIVATE tests)
         target_link_libraries(${test_case_name} PRIVATE testss2n)
         if (S2N_INTERN_LIBCRYPTO)
             # if libcrypto was interned, rewrite libcrypto symbols so use of internal functions will link correctly
@@ -521,15 +519,11 @@ if (BUILD_TESTING)
 
     add_executable(s2nc "bin/s2nc.c" "bin/echo.c" "bin/https.c" "bin/common.c")
     target_link_libraries(s2nc ${PROJECT_NAME})
-
-    target_include_directories(s2nc PRIVATE api)
     target_compile_options(s2nc PRIVATE -std=gnu99)
 
 
     add_executable(s2nd "bin/s2nd.c" "bin/echo.c" "bin/https.c" "bin/common.c")
     target_link_libraries(s2nd ${PROJECT_NAME})
-
-    target_include_directories(s2nd PRIVATE api)
     target_compile_options(s2nd PRIVATE -std=gnu99)
 
     if(S2N_LTO)
diff --git a/api/s2n.h b/api/s2n.h
index 6bce51c0342..15f6dbf9c7e 100644
--- a/api/s2n.h
+++ b/api/s2n.h
@@ -241,6 +241,27 @@ S2N_API extern int s2n_init(void);
  */
 S2N_API extern int s2n_cleanup(void);
 
+typedef enum {
+    S2N_FIPS_MODE_DISABLED = 0,
+    S2N_FIPS_MODE_ENABLED,
+} s2n_fips_mode;
+
+/**
+ * Determines whether s2n-tls is operating in FIPS mode.
+ *
+ * s2n-tls enters FIPS mode on initialization when the linked libcrypto has FIPS mode enabled. Some
+ * libcryptos, such as AWS-LC-FIPS, have FIPS mode enabled by default. With other libcryptos, such
+ * as OpenSSL, FIPS mode must be enabled before initialization by calling `FIPS_mode_set()`.
+ *
+ * s2n-tls MUST be linked to a FIPS libcrypto and MUST be in FIPS mode in order to comply with FIPS
+ * requirements. Applications desiring FIPS compliance should use this API to ensure that s2n-tls
+ * has been properly linked with a FIPS libcrypto and has successfully entered FIPS mode.
+ *
+ * @param fips_mode Set to the FIPS mode of s2n-tls.
+ * @returns S2N_SUCCESS on success. S2N_FAILURE on failure.
+ */
+S2N_API extern int s2n_get_fips_mode(s2n_fips_mode *fips_mode);
+
 /**
  * Creates a new s2n_config object. This object can (and should) be associated with many connection
  * objects.
@@ -1882,6 +1903,30 @@ S2N_API extern uint64_t s2n_connection_get_delay(struct s2n_connection *conn);
  */
 S2N_API extern int s2n_connection_set_cipher_preferences(struct s2n_connection *conn, const char *version);
 
+/**
+ * Used to indicate the type of key update that is being requested. For further 
+ * information refer to `s2n_connection_request_key_update`.
+*/
+typedef enum {
+    S2N_KEY_UPDATE_NOT_REQUESTED = 0,
+    S2N_KEY_UPDATE_REQUESTED
+} s2n_peer_key_update;
+
+/**
+ * Signals the connection to do a key_update at the next possible opportunity. Note that the resulting key update message
+ * will not be sent until `s2n_send` is called.
+ * 
+ * @param conn The connection object to trigger the key update on.
+ * @param peer_request Indicates if a key update should also be requested 
+ * of the peer. When set to `S2N_KEY_UPDATE_NOT_REQUESTED`, then only the sending
+ * key of `conn` will be updated. If set to `S2N_KEY_UPDATE_REQUESTED`, then 
+ * the sending key of conn will be updated AND the peer will be requested to 
+ * update their sending key. Note that s2n-tls currently only supports 
+ * `peer_request` being set to `S2N_KEY_UPDATE_NOT_REQUESTED` and will return
+ *  S2N_FAILURE if any other value is used.
+ * @returns S2N_SUCCESS on success. S2N_FAILURE on failure
+*/
+S2N_API extern int s2n_connection_request_key_update(struct s2n_connection *conn, s2n_peer_key_update peer_request);
 /**
  * Appends the provided application protocol to the preference list
  *
diff --git a/bindings/rust/s2n-tls/src/config.rs b/bindings/rust/s2n-tls/src/config.rs
index 3137a9d248d..9c42ad2b532 100644
--- a/bindings/rust/s2n-tls/src/config.rs
+++ b/bindings/rust/s2n-tls/src/config.rs
@@ -151,7 +151,6 @@ impl Drop for Config {
     }
 }
 
-#[derive(Default)]
 pub struct Builder {
     config: Config,
     load_system_certs: bool,
@@ -743,6 +742,12 @@ impl Builder {
     }
 }
 
+impl Default for Builder {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 pub(crate) struct Context {
     refcount: AtomicUsize,
     pub(crate) client_hello_callback: Option<Box<dyn ClientHelloCallback>>,
diff --git a/bindings/rust/s2n-tls/src/testing/s2n_tls.rs b/bindings/rust/s2n-tls/src/testing/s2n_tls.rs
index 1b6f12eae03..8fcf7c86db6 100644
--- a/bindings/rust/s2n-tls/src/testing/s2n_tls.rs
+++ b/bindings/rust/s2n-tls/src/testing/s2n_tls.rs
@@ -756,32 +756,36 @@ mod tests {
         // Load the server certificate into the trust store by overriding the OpenSSL default
         // certificate location.
         temp_env::with_var("SSL_CERT_FILE", Some(keypair.cert_path()), || {
-            let mut builder = Builder::new();
-            builder
-                .load_pem(keypair.cert(), keypair.key())
-                .unwrap()
-                .set_security_policy(&security::DEFAULT_TLS13)
-                .unwrap()
-                .set_verify_host_callback(InsecureAcceptAllCertificatesHandler {})
-                .unwrap();
+            // Test the Builder itself, and also the Builder produced by the Config builder() API.
+            for mut builder in [Builder::new(), Config::builder()] {
+                builder
+                    .load_pem(keypair.cert(), keypair.key())
+                    .unwrap()
+                    .set_security_policy(&security::DEFAULT_TLS13)
+                    .unwrap()
+                    .set_verify_host_callback(InsecureAcceptAllCertificatesHandler {})
+                    .unwrap();
 
-            // Disable loading system certificates
-            builder.with_system_certs(false).unwrap();
+                // Disable loading system certificates
+                builder.with_system_certs(false).unwrap();
 
-            let config = builder.build().unwrap();
-            let mut config_with_system_certs = config.clone();
+                let config = builder.build().unwrap();
+                let mut config_with_system_certs = config.clone();
 
-            let mut pair = tls_pair(config);
+                let mut pair = tls_pair(config);
 
-            // System certificates should not be loaded into the trust store. The handshake
-            // should fail since the certificate should not be trusted.
-            assert!(poll_tls_pair_result(&mut pair).is_err());
+                // System certificates should not be loaded into the trust store. The handshake
+                // should fail since the certificate should not be trusted.
+                assert!(poll_tls_pair_result(&mut pair).is_err());
 
-            // The handshake should succeed after trusting the certificate.
-            unsafe {
-                s2n_tls_sys::s2n_config_load_system_certs(config_with_system_certs.as_mut_ptr());
+                // The handshake should succeed after trusting the certificate.
+                unsafe {
+                    s2n_tls_sys::s2n_config_load_system_certs(
+                        config_with_system_certs.as_mut_ptr(),
+                    );
+                }
+                establish_connection(config_with_system_certs);
             }
-            establish_connection(config_with_system_certs);
         });
     }
 
diff --git a/crypto/s2n_fips.c b/crypto/s2n_fips.c
index 29229dd607d..ff73433a6ce 100644
--- a/crypto/s2n_fips.c
+++ b/crypto/s2n_fips.c
@@ -17,11 +17,14 @@
 
 #include <openssl/crypto.h>
 
+#include "utils/s2n_init.h"
+#include "utils/s2n_safety.h"
+
 #if defined(S2N_INTERN_LIBCRYPTO) && defined(OPENSSL_FIPS)
     #error "Interning with OpenSSL fips-validated libcrypto is not currently supported. See https://github.com/aws/s2n-tls/issues/2741"
 #endif
 
-static int s2n_fips_mode = 0;
+static bool s2n_fips_mode_enabled = false;
 
 /* FIPS mode can be checked if OpenSSL was configured and built for FIPS which then defines OPENSSL_FIPS.
  *
@@ -46,17 +49,25 @@ bool s2n_libcrypto_is_fips(void)
 
 int s2n_fips_init(void)
 {
-    s2n_fips_mode = 0;
-
-    if (s2n_libcrypto_is_fips()) {
-        s2n_fips_mode = 1;
-    }
-
-    return 0;
+    s2n_fips_mode_enabled = s2n_libcrypto_is_fips();
+    return S2N_SUCCESS;
 }
 
 /* Return 1 if FIPS mode is enabled, 0 otherwise. FIPS mode must be enabled prior to calling s2n_init(). */
-int s2n_is_in_fips_mode(void)
+bool s2n_is_in_fips_mode(void)
+{
+    return s2n_fips_mode_enabled;
+}
+
+int s2n_get_fips_mode(s2n_fips_mode *fips_mode)
 {
-    return s2n_fips_mode;
+    POSIX_ENSURE_REF(fips_mode);
+    *fips_mode = S2N_FIPS_MODE_DISABLED;
+    POSIX_ENSURE(s2n_is_initialized(), S2N_ERR_NOT_INITIALIZED);
+
+    if (s2n_is_in_fips_mode()) {
+        *fips_mode = S2N_FIPS_MODE_ENABLED;
+    }
+
+    return S2N_SUCCESS;
 }
diff --git a/crypto/s2n_fips.h b/crypto/s2n_fips.h
index f1047d52ae6..a353589199d 100644
--- a/crypto/s2n_fips.h
+++ b/crypto/s2n_fips.h
@@ -21,7 +21,7 @@
 #pragma once
 
 int s2n_fips_init(void);
-int s2n_is_in_fips_mode(void);
+bool s2n_is_in_fips_mode(void);
 bool s2n_libcrypto_is_fips(void);
 
 struct s2n_cipher_suite;
diff --git a/crypto/s2n_pkey.c b/crypto/s2n_pkey.c
index 190c73e303a..bcc57c42422 100644
--- a/crypto/s2n_pkey.c
+++ b/crypto/s2n_pkey.c
@@ -115,7 +115,11 @@ int s2n_pkey_match(const struct s2n_pkey *pub_key, const struct s2n_pkey *priv_k
 
 int s2n_pkey_free(struct s2n_pkey *key)
 {
-    if (key != NULL && key->free != NULL) {
+    if (key == NULL) {
+        return S2N_SUCCESS;
+    }
+
+    if (key->free != NULL) {
         POSIX_GUARD(key->free(key));
     }
 
diff --git a/scripts/s2n_safety_macros.py b/scripts/s2n_safety_macros.py
index fbd5a5d977b..9ca973eeca8 100644
--- a/scripts/s2n_safety_macros.py
+++ b/scripts/s2n_safety_macros.py
@@ -539,7 +539,7 @@ def cmp_check(op):
         * The size of the data pointed to by both the `destination` and `source` parameters,
           shall be at least `len` bytes.
         ''',
-        impl='__S2N_ENSURE_SAFE_MEMCPY((destination), (source), (len), {prefix}ENSURE_REF)',
+        impl='__S2N_ENSURE_SAFE_MEMMOVE((destination), (source), (len), {prefix}ENSURE_REF)',
         harness='''
         static {ret} {prefix}CHECKED_MEMCPY_harness(uint32_t* dest, uint32_t* source, size_t len)
         {{
diff --git a/stuffer/s2n_stuffer_network_order.c b/stuffer/s2n_stuffer_network_order.c
index 9db807a60cb..88927091eb2 100644
--- a/stuffer/s2n_stuffer_network_order.c
+++ b/stuffer/s2n_stuffer_network_order.c
@@ -21,10 +21,14 @@
 /* Writes length bytes of input to stuffer, in network order, starting from the smallest byte of input. */
 int s2n_stuffer_write_network_order(struct s2n_stuffer *stuffer, const uint64_t input, const uint8_t length)
 {
+    if (length == 0) {
+        return S2N_SUCCESS;
+    }
+    POSIX_ENSURE_REF(stuffer);
     POSIX_ENSURE(length <= sizeof(input), S2N_ERR_SAFETY);
     POSIX_GUARD(s2n_stuffer_skip_write(stuffer, length));
-    uint8_t *data = (stuffer->blob.data) ? (stuffer->blob.data + stuffer->write_cursor - length) : NULL;
-
+    POSIX_ENSURE_REF(stuffer->blob.data);
+    uint8_t *data = stuffer->blob.data + stuffer->write_cursor - length;
     for (int i = 0; i < length; i++) {
         S2N_INVARIANT(i <= length);
         uint8_t shift = (length - i - 1) * CHAR_BIT;
diff --git a/tests/cbmc/proofs/s2n_alloc/Makefile b/tests/cbmc/proofs/s2n_alloc/Makefile
index 92c2fd07206..7b6c5821968 100644
--- a/tests/cbmc/proofs/s2n_alloc/Makefile
+++ b/tests/cbmc/proofs/s2n_alloc/Makefile
@@ -40,7 +40,7 @@ PROJECT_SOURCES += $(SRCDIR)/utils/s2n_result.c
 # We abstract these functions because manual inspection demonstrates they are unreachable.
 REMOVE_FUNCTION_BODY += __CPROVER_file_local_s2n_mem_c_s2n_mem_cleanup_impl
 REMOVE_FUNCTION_BODY += s2n_blob_slice
-REMOVE_FUNCTION_BODY += s2n_ensure_memcpy_trace
+REMOVE_FUNCTION_BODY += s2n_ensure_memmove_trace
 
 UNWINDSET +=
 
diff --git a/tests/cbmc/proofs/s2n_array_init/Makefile b/tests/cbmc/proofs/s2n_array_init/Makefile
index 8f740b51045..48477fd21be 100644
--- a/tests/cbmc/proofs/s2n_array_init/Makefile
+++ b/tests/cbmc/proofs/s2n_array_init/Makefile
@@ -35,7 +35,7 @@ PROJECT_SOURCES += $(SRCDIR)/utils/s2n_safety.c
 
 # We abstract these functions because manual inspection demonstrates they are unreachable.
 REMOVE_FUNCTION_BODY += s2n_blob_slice
-REMOVE_FUNCTION_BODY += s2n_ensure_memcpy_trace
+REMOVE_FUNCTION_BODY += s2n_ensure_memmove_trace
 REMOVE_FUNCTION_BODY += __CPROVER_file_local_s2n_mem_c_s2n_mem_cleanup_impl
 
 UNWINDSET +=
diff --git a/tests/cbmc/proofs/s2n_array_new/Makefile b/tests/cbmc/proofs/s2n_array_new/Makefile
index 389c7f0192c..6cd64107a73 100644
--- a/tests/cbmc/proofs/s2n_array_new/Makefile
+++ b/tests/cbmc/proofs/s2n_array_new/Makefile
@@ -38,7 +38,7 @@ PROJECT_SOURCES += $(SRCDIR)/utils/s2n_safety.c
 
 # We abstract these functions because manual inspection demonstrates they are unreachable.
 REMOVE_FUNCTION_BODY += s2n_blob_slice
-REMOVE_FUNCTION_BODY += s2n_ensure_memcpy_trace
+REMOVE_FUNCTION_BODY += s2n_ensure_memmove_trace
 REMOVE_FUNCTION_BODY += __CPROVER_file_local_s2n_mem_c_s2n_mem_cleanup_impl
 
 UNWINDSET +=
diff --git a/tests/cbmc/proofs/s2n_dh_compute_shared_secret_as_client/Makefile b/tests/cbmc/proofs/s2n_dh_compute_shared_secret_as_client/Makefile
index ec8ef4fc519..cb7a239897c 100644
--- a/tests/cbmc/proofs/s2n_dh_compute_shared_secret_as_client/Makefile
+++ b/tests/cbmc/proofs/s2n_dh_compute_shared_secret_as_client/Makefile
@@ -39,7 +39,7 @@ PROJECT_SOURCES += $(SRCDIR)/utils/s2n_mem.c
 PROJECT_SOURCES += $(SRCDIR)/utils/s2n_result.c
 PROJECT_SOURCES += $(SRCDIR)/utils/s2n_safety.c
 
-UNWINDSET += s2n_stuffer_write_network_order.4:9
+UNWINDSET += s2n_stuffer_write_network_order.10:9
 
 # We abstract this function because manual inspection demonstrates it is unreachable.
 REMOVE_FUNCTION_BODY += __CPROVER_file_local_s2n_mem_c_s2n_mem_cleanup_impl
diff --git a/tests/cbmc/proofs/s2n_dh_params_to_p_g_Ys/Makefile b/tests/cbmc/proofs/s2n_dh_params_to_p_g_Ys/Makefile
index 94ca0745414..33bba982d1f 100644
--- a/tests/cbmc/proofs/s2n_dh_params_to_p_g_Ys/Makefile
+++ b/tests/cbmc/proofs/s2n_dh_params_to_p_g_Ys/Makefile
@@ -42,6 +42,6 @@ REMOVE_FUNCTION_BODY += s2n_free
 REMOVE_FUNCTION_BODY += s2n_realloc
 REMOVE_FUNCTION_BODY += s2n_stuffer_wipe
 
-UNWINDSET += s2n_stuffer_write_network_order.4:9
+UNWINDSET += s2n_stuffer_write_network_order.10:9
 
 include ../Makefile.common
diff --git a/tests/cbmc/proofs/s2n_set_new/Makefile b/tests/cbmc/proofs/s2n_set_new/Makefile
index 6322ae4ce0e..5cf2f575ea5 100644
--- a/tests/cbmc/proofs/s2n_set_new/Makefile
+++ b/tests/cbmc/proofs/s2n_set_new/Makefile
@@ -42,7 +42,7 @@ PROJECT_SOURCES += $(SRCDIR)/utils/s2n_set.c
 
 # We abstract these functions because manual inspection demonstrates they are unreachable.
 REMOVE_FUNCTION_BODY += s2n_blob_slice
-REMOVE_FUNCTION_BODY += s2n_ensure_memcpy_trace
+REMOVE_FUNCTION_BODY += s2n_ensure_memmove_trace
 REMOVE_FUNCTION_BODY += __CPROVER_file_local_s2n_mem_c_s2n_mem_cleanup_impl
 
 UNWINDSET +=
diff --git a/tests/cbmc/proofs/s2n_stuffer_alloc/Makefile b/tests/cbmc/proofs/s2n_stuffer_alloc/Makefile
index 59795b1e168..db954284f82 100644
--- a/tests/cbmc/proofs/s2n_stuffer_alloc/Makefile
+++ b/tests/cbmc/proofs/s2n_stuffer_alloc/Makefile
@@ -40,7 +40,7 @@ PROJECT_SOURCES += $(SRCDIR)/utils/s2n_safety.c
 # We abstract these functions because manual inspection demonstrates they are unreachable.
 REMOVE_FUNCTION_BODY += __CPROVER_file_local_s2n_mem_c_s2n_mem_cleanup_impl
 REMOVE_FUNCTION_BODY += s2n_blob_slice
-REMOVE_FUNCTION_BODY += s2n_ensure_memcpy_trace
+REMOVE_FUNCTION_BODY += s2n_ensure_memmove_trace
 
 UNWINDSET +=
 
diff --git a/tests/cbmc/proofs/s2n_stuffer_growable_alloc/Makefile b/tests/cbmc/proofs/s2n_stuffer_growable_alloc/Makefile
index 48ca5bebc0a..4a11bcc8189 100644
--- a/tests/cbmc/proofs/s2n_stuffer_growable_alloc/Makefile
+++ b/tests/cbmc/proofs/s2n_stuffer_growable_alloc/Makefile
@@ -38,7 +38,7 @@ PROJECT_SOURCES += $(SRCDIR)/utils/s2n_safety.c
 # We abstract these functions because manual inspection demonstrates they are unreachable.
 REMOVE_FUNCTION_BODY += __CPROVER_file_local_s2n_mem_c_s2n_mem_cleanup_impl
 REMOVE_FUNCTION_BODY += s2n_blob_slice
-REMOVE_FUNCTION_BODY += s2n_ensure_memcpy_trace
+REMOVE_FUNCTION_BODY += s2n_ensure_memmove_trace
 
 UNWINDSET +=
 
diff --git a/tests/cbmc/proofs/s2n_stuffer_resize_if_empty/Makefile b/tests/cbmc/proofs/s2n_stuffer_resize_if_empty/Makefile
index daac401569b..41b69d86b55 100644
--- a/tests/cbmc/proofs/s2n_stuffer_resize_if_empty/Makefile
+++ b/tests/cbmc/proofs/s2n_stuffer_resize_if_empty/Makefile
@@ -35,7 +35,7 @@ PROJECT_SOURCES += $(SRCDIR)/utils/s2n_result.c
 # We abstract these functions because manual inspection demonstrates they are unreachable.
 REMOVE_FUNCTION_BODY += s2n_calculate_stacktrace
 REMOVE_FUNCTION_BODY += s2n_blob_slice
-REMOVE_FUNCTION_BODY += s2n_ensure_memcpy_trace
+REMOVE_FUNCTION_BODY += s2n_ensure_memmove_trace
 REMOVE_FUNCTION_BODY += __CPROVER_file_local_s2n_mem_c_s2n_mem_cleanup_impl
 
 UNWINDSET +=
diff --git a/tests/cbmc/proofs/s2n_stuffer_write_network_order/Makefile b/tests/cbmc/proofs/s2n_stuffer_write_network_order/Makefile
index 4c8f38b8e79..ba093b9041a 100644
--- a/tests/cbmc/proofs/s2n_stuffer_write_network_order/Makefile
+++ b/tests/cbmc/proofs/s2n_stuffer_write_network_order/Makefile
@@ -38,7 +38,7 @@ REMOVE_FUNCTION_BODY += __CPROVER_file_local_s2n_mem_c_s2n_mem_cleanup_impl
 REMOVE_FUNCTION_BODY += s2n_blob_slice
 REMOVE_FUNCTION_BODY += s2n_stuffer_wipe
 
-UNWINDSET += s2n_stuffer_write_network_order.4:9
+UNWINDSET += s2n_stuffer_write_network_order.10:9
 UNWINDSET += s2n_stuffer_write_network_order_harness.0:9
 
 include ../Makefile.common
diff --git a/tests/cbmc/proofs/s2n_stuffer_write_reservation/Makefile b/tests/cbmc/proofs/s2n_stuffer_write_reservation/Makefile
index fe8370b37f7..bc921b1d3ee 100644
--- a/tests/cbmc/proofs/s2n_stuffer_write_reservation/Makefile
+++ b/tests/cbmc/proofs/s2n_stuffer_write_reservation/Makefile
@@ -48,13 +48,6 @@ REMOVE_FUNCTION_BODY += s2n_stuffer_wipe
 REMOVE_FUNCTION_BODY += s2n_stuffer_wipe_n
 REMOVE_FUNCTION_BODY += __CPROVER_file_local_s2n_mem_c_s2n_mem_cleanup_impl
 
-UNWINDSET += s2n_stuffer_write_network_order.0:$(MAX_WRITE_NETWORK_ORDER)
-UNWINDSET += s2n_stuffer_write_network_order.1:$(MAX_WRITE_NETWORK_ORDER)
-UNWINDSET += s2n_stuffer_write_network_order.2:$(MAX_WRITE_NETWORK_ORDER)
-UNWINDSET += s2n_stuffer_write_network_order.3:$(MAX_WRITE_NETWORK_ORDER)
-UNWINDSET += s2n_stuffer_write_network_order.4:$(MAX_WRITE_NETWORK_ORDER)
-UNWINDSET += s2n_stuffer_write_network_order.5:$(MAX_WRITE_NETWORK_ORDER)
-UNWINDSET += s2n_stuffer_write_network_order.6:$(MAX_WRITE_NETWORK_ORDER)
-UNWINDSET += s2n_stuffer_write_network_order.7:$(MAX_WRITE_NETWORK_ORDER)
+UNWINDSET += s2n_stuffer_write_network_order.10:$(MAX_WRITE_NETWORK_ORDER)
 
 include ../Makefile.common
diff --git a/tests/cbmc/proofs/s2n_stuffer_write_uint16/Makefile b/tests/cbmc/proofs/s2n_stuffer_write_uint16/Makefile
index 73c61bcecad..de513abf4e9 100644
--- a/tests/cbmc/proofs/s2n_stuffer_write_uint16/Makefile
+++ b/tests/cbmc/proofs/s2n_stuffer_write_uint16/Makefile
@@ -36,6 +36,6 @@ PROJECT_SOURCES += $(SRCDIR)/utils/s2n_result.c
 REMOVE_FUNCTION_BODY += s2n_blob_slice
 REMOVE_FUNCTION_BODY += s2n_stuffer_wipe
 
-UNWINDSET += s2n_stuffer_write_network_order.4:$(shell echo $$((1 + $(SIZEOF_UINT16))))
+UNWINDSET += s2n_stuffer_write_network_order.10:$(shell echo $$((1 + $(SIZEOF_UINT16))))
 
 include ../Makefile.common
diff --git a/tests/cbmc/proofs/s2n_stuffer_write_uint24/Makefile b/tests/cbmc/proofs/s2n_stuffer_write_uint24/Makefile
index acba5cf7b1e..0ee330db573 100644
--- a/tests/cbmc/proofs/s2n_stuffer_write_uint24/Makefile
+++ b/tests/cbmc/proofs/s2n_stuffer_write_uint24/Makefile
@@ -36,6 +36,6 @@ PROJECT_SOURCES += $(SRCDIR)/utils/s2n_result.c
 REMOVE_FUNCTION_BODY += s2n_blob_slice
 REMOVE_FUNCTION_BODY += s2n_stuffer_wipe
 
-UNWINDSET += s2n_stuffer_write_network_order.4:$(shell echo $$((1 + $(SIZEOF_UINT24))))
+UNWINDSET += s2n_stuffer_write_network_order.10:$(shell echo $$((1 + $(SIZEOF_UINT24))))
 
 include ../Makefile.common
diff --git a/tests/cbmc/proofs/s2n_stuffer_write_uint32/Makefile b/tests/cbmc/proofs/s2n_stuffer_write_uint32/Makefile
index aece6e2f0d0..bec46adf7eb 100644
--- a/tests/cbmc/proofs/s2n_stuffer_write_uint32/Makefile
+++ b/tests/cbmc/proofs/s2n_stuffer_write_uint32/Makefile
@@ -36,6 +36,6 @@ PROJECT_SOURCES += $(SRCDIR)/utils/s2n_result.c
 REMOVE_FUNCTION_BODY += s2n_blob_slice
 REMOVE_FUNCTION_BODY += s2n_stuffer_wipe
 
-UNWINDSET += s2n_stuffer_write_network_order.4:$(shell echo $$((1 + $(SIZEOF_UINT32))))
+UNWINDSET += s2n_stuffer_write_network_order.10:$(shell echo $$((1 + $(SIZEOF_UINT32))))
 
 include ../Makefile.common
diff --git a/tests/cbmc/proofs/s2n_stuffer_write_uint64/Makefile b/tests/cbmc/proofs/s2n_stuffer_write_uint64/Makefile
index 04f1c6b5aae..8e339851469 100644
--- a/tests/cbmc/proofs/s2n_stuffer_write_uint64/Makefile
+++ b/tests/cbmc/proofs/s2n_stuffer_write_uint64/Makefile
@@ -36,6 +36,6 @@ PROJECT_SOURCES += $(SRCDIR)/utils/s2n_result.c
 REMOVE_FUNCTION_BODY += s2n_blob_slice
 REMOVE_FUNCTION_BODY += s2n_stuffer_wipe
 
-UNWINDSET += s2n_stuffer_write_network_order.4:$(shell echo $$((1 + $(SIZEOF_UINT64))))
+UNWINDSET += s2n_stuffer_write_network_order.10:$(shell echo $$((1 + $(SIZEOF_UINT64))))
 
 include ../Makefile.common
diff --git a/tests/cbmc/proofs/s2n_stuffer_write_vector_size/Makefile b/tests/cbmc/proofs/s2n_stuffer_write_vector_size/Makefile
index cf3fc56cd15..350684a0681 100644
--- a/tests/cbmc/proofs/s2n_stuffer_write_vector_size/Makefile
+++ b/tests/cbmc/proofs/s2n_stuffer_write_vector_size/Makefile
@@ -44,13 +44,6 @@ REMOVE_FUNCTION_BODY += s2n_stuffer_resize
 REMOVE_FUNCTION_BODY += s2n_stuffer_wipe_n
 REMOVE_FUNCTION_BODY += __CPROVER_file_local_s2n_mem_c_s2n_mem_cleanup_impl
 
-UNWINDSET += s2n_stuffer_write_network_order.0:$(MAX_WRITE_NETWORK_ORDER)
-UNWINDSET += s2n_stuffer_write_network_order.1:$(MAX_WRITE_NETWORK_ORDER)
-UNWINDSET += s2n_stuffer_write_network_order.2:$(MAX_WRITE_NETWORK_ORDER)
-UNWINDSET += s2n_stuffer_write_network_order.3:$(MAX_WRITE_NETWORK_ORDER)
-UNWINDSET += s2n_stuffer_write_network_order.4:$(MAX_WRITE_NETWORK_ORDER)
-UNWINDSET += s2n_stuffer_write_network_order.5:$(MAX_WRITE_NETWORK_ORDER)
-UNWINDSET += s2n_stuffer_write_network_order.6:$(MAX_WRITE_NETWORK_ORDER)
-UNWINDSET += s2n_stuffer_write_network_order.7:$(MAX_WRITE_NETWORK_ORDER)
+UNWINDSET += s2n_stuffer_write_network_order.10:$(MAX_WRITE_NETWORK_ORDER)
 
 include ../Makefile.common
diff --git a/tests/cbmc/stubs/s2n_ensure.c b/tests/cbmc/stubs/s2n_ensure.c
index 01ff888062f..ae0e5a82c47 100644
--- a/tests/cbmc/stubs/s2n_ensure.c
+++ b/tests/cbmc/stubs/s2n_ensure.c
@@ -15,7 +15,7 @@
 
 #include "utils/s2n_safety.h"
 
-void* s2n_ensure_memcpy_trace(void *restrict to, const void *restrict from, size_t size)
+void* s2n_ensure_memmove_trace(void *to, const void *from, size_t size)
 {
     if (to == NULL || from == NULL) {
         return NULL;
diff --git a/tests/cbmc/stubs/s2n_is_in_fips_mode.c b/tests/cbmc/stubs/s2n_is_in_fips_mode.c
index 8a76d11bc6d..7ee61b05510 100644
--- a/tests/cbmc/stubs/s2n_is_in_fips_mode.c
+++ b/tests/cbmc/stubs/s2n_is_in_fips_mode.c
@@ -17,18 +17,18 @@
 
 #include "crypto/s2n_fips.h"
 
-static int flag          = 0;
-static int s2n_fips_mode = 0;
+static bool flag = 0;
+static bool s2n_fips_mode_enabled = 0;
 
 /**
  * Return 1 if FIPS mode is set, 0 otherwise,
  * where FIPS mode is set nondeterministically on first call.
  */
-int s2n_is_in_fips_mode()
+bool s2n_is_in_fips_mode()
 {
     if (flag == 0) {
-        s2n_fips_mode = nondet_bool() ? 1 : 0;
-        flag          = 1;
+        s2n_fips_mode_enabled = nondet_bool() ? 1 : 0;
+        flag = 1;
     }
-    return s2n_fips_mode;
+    return s2n_fips_mode_enabled;
 }
diff --git a/tests/features/S2N___RESTRICT__SUPPORTED.c b/tests/features/S2N___RESTRICT__SUPPORTED.c
deleted file mode 100644
index b29c32ef9ad..00000000000
--- a/tests/features/S2N___RESTRICT__SUPPORTED.c
+++ /dev/null
@@ -1,27 +0,0 @@
-/*
- * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
- *
- * Licensed under the Apache License, Version 2.0 (the "License").
- * You may not use this file except in compliance with the License.
- * A copy of the License is located at
- *
- *  http://aws.amazon.com/apache2.0
- *
- * or in the "license" file accompanying this file. This file is distributed
- * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
- * express or implied. See the License for the specific language governing
- * permissions and limitations under the License.
- */
-
-void swap(int *__restrict__ left, int *__restrict__ right) {
-    int temp = *left;
-    *left = *right;
-    *right = temp;
-}
-
-int main() {
-    int a = 1, b = 2;
-    swap(&a, &b);
-    return 0;
-}
-
diff --git a/tests/features/S2N___RESTRICT__SUPPORTED.flags b/tests/features/S2N___RESTRICT__SUPPORTED.flags
deleted file mode 100644
index 2f41be663b2..00000000000
--- a/tests/features/S2N___RESTRICT__SUPPORTED.flags
+++ /dev/null
@@ -1 +0,0 @@
--Werror
diff --git a/tests/sidetrail/working/stubs/s2n_ensure.h b/tests/sidetrail/working/stubs/s2n_ensure.h
index 521e3e56f55..179f5a52b19 100644
--- a/tests/sidetrail/working/stubs/s2n_ensure.h
+++ b/tests/sidetrail/working/stubs/s2n_ensure.h
@@ -31,7 +31,10 @@ void *s2n_sidetrail_memset(void * ptr, int value, size_t num);
 #define __S2N_ENSURE_PRECONDITION( result )                S2N_RESULT_OK
 #define __S2N_ENSURE_POSTCONDITION( result )               S2N_RESULT_OK
 
-#define __S2N_ENSURE_SAFE_MEMCPY( d , s , n , guard )      do { memcpy((d), (s), (n)); } while(0)
+/* memmove isn't supported, so use memcpy instead.
+ * For the purposes of these proofs, there should be no useful difference.
+ */
+#define __S2N_ENSURE_SAFE_MEMMOVE( d , s , n , guard )      do { memcpy((d), (s), (n)); } while(0)
 
 #define __S2N_ENSURE_SAFE_MEMSET( d , c , n , guard )      \
   do {                                                     \
diff --git a/tests/unit/s2n_build_test.c b/tests/unit/s2n_build_test.c
index 75195fe0d2a..e7f40949d15 100644
--- a/tests/unit/s2n_build_test.c
+++ b/tests/unit/s2n_build_test.c
@@ -84,6 +84,18 @@ int main()
         END_TEST();
     }
 
+    /* Ensure that FIPS mode is enabled when linked to AWS-LC-FIPS, and disabled when linked to AWS-LC */
+    if (strstr(s2n_libcrypto, "awslc") != NULL) {
+        s2n_fips_mode fips_mode = S2N_FIPS_MODE_DISABLED;
+        EXPECT_SUCCESS(s2n_get_fips_mode(&fips_mode));
+
+        if (strstr(s2n_libcrypto, "fips") != NULL) {
+            EXPECT_EQUAL(fips_mode, S2N_FIPS_MODE_ENABLED);
+        } else {
+            EXPECT_EQUAL(fips_mode, S2N_FIPS_MODE_DISABLED);
+        }
+    }
+
     char s2n_libcrypto_copy[MAX_LIBCRYPTO_NAME_LEN] = { 0 };
     EXPECT_TRUE(strlen(s2n_libcrypto) < MAX_LIBCRYPTO_NAME_LEN);
     EXPECT_OK(s2n_test_lowercase_copy(s2n_libcrypto, &s2n_libcrypto_copy[0], s2n_array_len(s2n_libcrypto_copy)));
diff --git a/tests/unit/s2n_fips_test.c b/tests/unit/s2n_fips_test.c
new file mode 100644
index 00000000000..c4e5bdc134e
--- /dev/null
+++ b/tests/unit/s2n_fips_test.c
@@ -0,0 +1,53 @@
+/*
+* Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+*
+* Licensed under the Apache License, Version 2.0 (the "License").
+* You may not use this file except in compliance with the License.
+* A copy of the License is located at
+*
+*  http://aws.amazon.com/apache2.0
+*
+* or in the "license" file accompanying this file. This file is distributed
+* on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
+* express or implied. See the License for the specific language governing
+* permissions and limitations under the License.
+*/
+
+#include "crypto/s2n_fips.h"
+
+#include "api/s2n.h"
+#include "s2n_test.h"
+
+int main()
+{
+    BEGIN_TEST_NO_INIT();
+
+    /* s2n_get_fips_mode() fails before init */
+    {
+        s2n_fips_mode fips_mode = S2N_FIPS_MODE_ENABLED;
+        EXPECT_FAILURE_WITH_ERRNO(s2n_get_fips_mode(&fips_mode), S2N_ERR_NOT_INITIALIZED);
+        EXPECT_EQUAL(fips_mode, S2N_FIPS_MODE_DISABLED);
+    }
+
+    EXPECT_SUCCESS(s2n_init());
+
+    /* Test s2n_get_fips_mode() after init */
+    {
+        /* Safety */
+        EXPECT_FAILURE_WITH_ERRNO(s2n_get_fips_mode(NULL), S2N_ERR_NULL);
+
+        /* FIPS mode matches s2n_is_in_fips_mode() */
+        {
+            s2n_fips_mode fips_mode = S2N_FIPS_MODE_DISABLED;
+            EXPECT_SUCCESS(s2n_get_fips_mode(&fips_mode));
+
+            if (s2n_is_in_fips_mode()) {
+                EXPECT_EQUAL(fips_mode, S2N_FIPS_MODE_ENABLED);
+            } else {
+                EXPECT_EQUAL(fips_mode, S2N_FIPS_MODE_DISABLED);
+            }
+        }
+    }
+
+    END_TEST();
+}
diff --git a/tests/unit/s2n_key_update_test.c b/tests/unit/s2n_key_update_test.c
index 23955cdd2a8..be8bf8b1874 100644
--- a/tests/unit/s2n_key_update_test.c
+++ b/tests/unit/s2n_key_update_test.c
@@ -333,7 +333,7 @@ int main(int argc, char **argv)
             EXPECT_SUCCESS(s2n_stuffer_growable_alloc(&stuffer, 0));
             EXPECT_SUCCESS(s2n_connection_set_io_stuffers(&stuffer, &stuffer, client_conn));
 
-            s2n_atomic_flag_set(&client_conn->key_update_pending);
+            EXPECT_SUCCESS(s2n_connection_request_key_update(client_conn, S2N_KEY_UPDATE_NOT_REQUESTED));
 
             s2n_blocked_status blocked = 0;
             EXPECT_SUCCESS(s2n_key_update_send(client_conn, &blocked));
@@ -677,5 +677,27 @@ int main(int argc, char **argv)
         }
     }
 
+    /* s2n_connection_key_update_requested */
+    {
+        /* null safety */
+        {
+            EXPECT_FAILURE_WITH_ERRNO(s2n_connection_request_key_update(NULL, S2N_KEY_UPDATE_NOT_REQUESTED), S2N_ERR_NULL);
+        };
+
+        /* usage */
+        {
+            DEFER_CLEANUP(struct s2n_connection *conn = s2n_connection_new(S2N_SERVER), s2n_connection_ptr_free);
+            EXPECT_FAILURE_WITH_ERRNO(s2n_connection_request_key_update(conn, S2N_KEY_UPDATE_REQUESTED), S2N_ERR_INVALID_ARGUMENT);
+        };
+
+        /* happy path */
+        {
+            DEFER_CLEANUP(struct s2n_connection *conn = s2n_connection_new(S2N_SERVER), s2n_connection_ptr_free);
+            EXPECT_FALSE(s2n_atomic_flag_test(&conn->key_update_pending));
+            EXPECT_SUCCESS(s2n_connection_request_key_update(conn, S2N_KEY_UPDATE_NOT_REQUESTED));
+            EXPECT_TRUE(s2n_atomic_flag_test(&conn->key_update_pending));
+        };
+    };
+
     END_TEST();
 }
diff --git a/tests/unit/s2n_key_update_threads_test.c b/tests/unit/s2n_key_update_threads_test.c
index 0a7ef4dd4c0..d54807c6587 100644
--- a/tests/unit/s2n_key_update_threads_test.c
+++ b/tests/unit/s2n_key_update_threads_test.c
@@ -35,7 +35,7 @@
     _##name##_record_alg.encryption_limit = limit;                       \
     name.record_alg = &_##name##_record_alg;
 
-S2N_RESULT s2n_set_key_update_request_for_testing(keyupdate_request request);
+S2N_RESULT s2n_set_key_update_request_for_testing(s2n_peer_key_update request);
 
 static void *s2n_send_random_data(void *arg)
 {
diff --git a/tls/s2n_key_update.c b/tls/s2n_key_update.c
index d10d7c5b244..90c49c9756e 100644
--- a/tls/s2n_key_update.c
+++ b/tls/s2n_key_update.c
@@ -24,12 +24,12 @@
 #include "utils/s2n_atomic.h"
 #include "utils/s2n_safety.h"
 
-static keyupdate_request key_update_request_val = S2N_KEY_UPDATE_NOT_REQUESTED;
+static s2n_peer_key_update key_update_request_val = S2N_KEY_UPDATE_NOT_REQUESTED;
 
 int s2n_key_update_write(struct s2n_blob *out);
 int s2n_check_record_limit(struct s2n_connection *conn, struct s2n_blob *sequence_number);
 
-S2N_RESULT s2n_set_key_update_request_for_testing(keyupdate_request request)
+S2N_RESULT s2n_set_key_update_request_for_testing(s2n_peer_key_update request)
 {
     RESULT_ENSURE(s2n_in_unit_test(), S2N_ERR_NOT_IN_UNIT_TEST);
     key_update_request_val = request;
@@ -146,3 +146,12 @@ int s2n_check_record_limit(struct s2n_connection *conn, struct s2n_blob *sequenc
 
     return S2N_SUCCESS;
 }
+
+int s2n_connection_request_key_update(struct s2n_connection *conn, s2n_peer_key_update peer_request)
+{
+    POSIX_ENSURE_REF(conn);
+    /* s2n-tls does not currently support requesting key updates from peers */
+    POSIX_ENSURE(peer_request == S2N_KEY_UPDATE_NOT_REQUESTED, S2N_ERR_INVALID_ARGUMENT);
+    s2n_atomic_flag_set(&conn->key_update_pending);
+    return S2N_SUCCESS;
+}
diff --git a/tls/s2n_key_update.h b/tls/s2n_key_update.h
index 2b787f08487..79a103d8261 100644
--- a/tls/s2n_key_update.h
+++ b/tls/s2n_key_update.h
@@ -25,10 +25,5 @@ typedef enum {
     RECEIVING
 } keyupdate_status;
 
-typedef enum {
-    S2N_KEY_UPDATE_NOT_REQUESTED = 0,
-    S2N_KEY_UPDATE_REQUESTED
-} keyupdate_request;
-
 int s2n_key_update_recv(struct s2n_connection *conn, struct s2n_stuffer *request);
 int s2n_key_update_send(struct s2n_connection *conn, s2n_blocked_status *blocked);
diff --git a/tls/s2n_security_rules.c b/tls/s2n_security_rules.c
index ebeefe99430..2d1513d3909 100644
--- a/tls/s2n_security_rules.c
+++ b/tls/s2n_security_rules.c
@@ -219,7 +219,7 @@ S2N_CLEANUP_RESULT s2n_security_rule_result_free(struct s2n_security_rule_result
 {
     if (result) {
         RESULT_GUARD_POSIX(s2n_stuffer_free(&result->output));
+        *result = (struct s2n_security_rule_result){ 0 };
     }
-    *result = (struct s2n_security_rule_result){ 0 };
     return S2N_RESULT_OK;
 }
diff --git a/utils/s2n_ensure.c b/utils/s2n_ensure.c
index 5824f9b6186..c2350740462 100644
--- a/utils/s2n_ensure.c
+++ b/utils/s2n_ensure.c
@@ -15,7 +15,7 @@
 
 #include "utils/s2n_safety.h"
 
-void *s2n_ensure_memcpy_trace(void *restrict to, const void *restrict from, size_t size)
+void *s2n_ensure_memmove_trace(void *to, const void *from, size_t size)
 {
     PTR_ENSURE_REF(to);
     PTR_ENSURE_REF(from);
diff --git a/utils/s2n_ensure.h b/utils/s2n_ensure.h
index c072d93e952..890cca162b5 100644
--- a/utils/s2n_ensure.h
+++ b/utils/s2n_ensure.h
@@ -60,13 +60,13 @@
     #define __S2N_ENSURE_POSTCONDITION(result) (s2n_likely(s2n_result_is_ok(result)) ? S2N_RESULT_OK : S2N_RESULT_ERROR)
 #endif
 
-#define __S2N_ENSURE_SAFE_MEMCPY(d, s, n, guard)                    \
-    do {                                                            \
-        __typeof(n) __tmp_n = (n);                                  \
-        if (s2n_likely(__tmp_n)) {                                  \
-            void *r = s2n_ensure_memcpy_trace((d), (s), (__tmp_n)); \
-            guard(r);                                               \
-        }                                                           \
+#define __S2N_ENSURE_SAFE_MEMMOVE(d, s, n, guard)                    \
+    do {                                                             \
+        __typeof(n) __tmp_n = (n);                                   \
+        if (s2n_likely(__tmp_n)) {                                   \
+            void *r = s2n_ensure_memmove_trace((d), (s), (__tmp_n)); \
+            guard(r);                                                \
+        }                                                            \
     } while (0)
 
 #define __S2N_ENSURE_SAFE_MEMSET(d, c, n, guard) \
@@ -90,23 +90,7 @@
     #define __S2N_ENSURE_CHECKED_RETURN(v) return v
 #endif
 
-/**
- * `restrict` is a part of the c99 standard and will work with any C compiler. If you're trying to
- * compile with a C++ compiler `restrict` is invalid. However some C++ compilers support the behavior
- * of `restrict` using the `__restrict__` keyword. Therefore if the compiler supports `__restrict__`
- * use it.
- *
- * This is helpful for the benchmarks in tests/benchmark which use Google's Benchmark library and
- * are all written in C++.
- *
- * https://gcc.gnu.org/onlinedocs/gcc/Restricted-Pointers.html
- *
- */
-#if defined(S2N___RESTRICT__SUPPORTED)
-void *s2n_ensure_memcpy_trace(void *__restrict__ to, const void *__restrict__ from, size_t size);
-#else
-void *s2n_ensure_memcpy_trace(void *restrict to, const void *restrict from, size_t size);
-#endif
+void *s2n_ensure_memmove_trace(void *to, const void *from, size_t size);
 
 /**
  * These macros should not be used in validate functions.
diff --git a/utils/s2n_map.c b/utils/s2n_map.c
index b1ad6721c09..ee8bafd7c32 100644
--- a/utils/s2n_map.c
+++ b/utils/s2n_map.c
@@ -32,6 +32,7 @@
 static S2N_RESULT s2n_map_slot(const struct s2n_map *map, struct s2n_blob *key, uint32_t *slot)
 {
     RESULT_ENSURE_REF(map);
+    RESULT_ENSURE(map->capacity != 0, S2N_ERR_SAFETY);
     union {
         uint8_t u8[32];
         uint32_t u32[8];
diff --git a/utils/s2n_safety_macros.h b/utils/s2n_safety_macros.h
index 33e5133dca4..e3896e8c360 100644
--- a/utils/s2n_safety_macros.h
+++ b/utils/s2n_safety_macros.h
@@ -161,7 +161,7 @@
  * * The size of the data pointed to by both the `destination` and `source` parameters,
  *   shall be at least `len` bytes.
  */
-#define RESULT_CHECKED_MEMCPY(destination, source, len)        __S2N_ENSURE_SAFE_MEMCPY((destination), (source), (len), RESULT_ENSURE_REF)
+#define RESULT_CHECKED_MEMCPY(destination, source, len)        __S2N_ENSURE_SAFE_MEMMOVE((destination), (source), (len), RESULT_ENSURE_REF)
 
 /**
  * Performs a safer memset
@@ -357,7 +357,7 @@
  * * The size of the data pointed to by both the `destination` and `source` parameters,
  *   shall be at least `len` bytes.
  */
-#define POSIX_CHECKED_MEMCPY(destination, source, len)        __S2N_ENSURE_SAFE_MEMCPY((destination), (source), (len), POSIX_ENSURE_REF)
+#define POSIX_CHECKED_MEMCPY(destination, source, len)        __S2N_ENSURE_SAFE_MEMMOVE((destination), (source), (len), POSIX_ENSURE_REF)
 
 /**
  * DEPRECATED: all methods (except those in s2n.h) should return s2n_result.
@@ -563,7 +563,7 @@
  * * The size of the data pointed to by both the `destination` and `source` parameters,
  *   shall be at least `len` bytes.
  */
-#define PTR_CHECKED_MEMCPY(destination, source, len)          __S2N_ENSURE_SAFE_MEMCPY((destination), (source), (len), PTR_ENSURE_REF)
+#define PTR_CHECKED_MEMCPY(destination, source, len)          __S2N_ENSURE_SAFE_MEMMOVE((destination), (source), (len), PTR_ENSURE_REF)
 
 /**
  * DEPRECATED: all methods (except those in s2n.h) should return s2n_result.