diff --git a/Android.bp b/Android.bp
index 79914bd..8293c37 100644
--- a/Android.bp
+++ b/Android.bp
@@ -110,6 +110,9 @@ cc_library_static {
     export_include_dirs: ["."],
     shared_libs: ["libbase"],
     static_libs: ["libfs_mgr"],
+    cflags: [
+        "-DAVB_AB_I_UNDERSTAND_LIBAVB_AB_IS_DEPRECATED",
+    ],
     srcs: [
         "libavb/avb_sysdeps_posix.c",
         "libavb_ab/avb_ab_flow.c",
@@ -136,6 +139,7 @@ cc_library_host_static {
     export_include_dirs: ["."],
     cflags: [
         "-fno-stack-protector",
+        "-DAVB_AB_I_UNDERSTAND_LIBAVB_AB_IS_DEPRECATED",
     ],
     srcs: ["libavb_ab/avb_ab_flow.c"],
 }
@@ -178,6 +182,7 @@ cc_test_host {
     ],
     cflags: [
             "-Wno-missing-prototypes",
+            "-DAVB_AB_I_UNDERSTAND_LIBAVB_AB_IS_DEPRECATED",
     ],
     srcs: [
         "test/avb_ab_flow_unittest.cc",
@@ -196,6 +201,9 @@ cc_test_host {
 cc_library_host_static {
     name: "libavb_host_user_code_test",
     defaults: ["avb_defaults"],
+    cflags: [
+        "-DAVB_AB_I_UNDERSTAND_LIBAVB_AB_IS_DEPRECATED",
+    ],
     srcs: ["test/user_code_test.cc"],
 }
 
@@ -211,5 +219,8 @@ cc_library {
         "libbase",
         "libcutils",
     ],
+    cflags: [
+        "-DAVB_AB_I_UNDERSTAND_LIBAVB_AB_IS_DEPRECATED",
+    ],
     srcs: ["boot_control/boot_control_avb.c"],
 }
diff --git a/README.md b/README.md
index 8728e72..c07ec7e 100644
--- a/README.md
+++ b/README.md
@@ -174,17 +174,21 @@ validation operation (see `avb_validate_vbmeta_public_key()` in
       expected to be provided by the platform is defined in
       `avb_sysdeps.h`. If the platform provides the standard C runtime
       `avb_sysdeps_posix.c` can be used.
-* `libavb_ab/`
-    + An experimental A/B implementation for use in boot loaders
-      and AVB examples.
 * `libavb_atx/`
     + An Android Things Extension for validating public key metadata.
 * `libavb_user/`
     + Contains an `AvbOps` implementation suitable for use in Android
       userspace. This is used in `boot_control.avb` and `avbctl`.
+* `libavb_ab/`
+    + An experimental A/B implementation for use in boot loaders and
+      AVB examples. **NOTE**: This code is *DEPRECATED* and you must
+      define `AVB_AB_I_UNDERSTAND_LIBAVB_AB_IS_DEPRECATED` to use
+      it. The code will be removed Jun 1 2018.
 * `boot_control/`
     + An implementation of the Android `boot_control` HAL for use with
       boot loaders using the experimental `libavb_ab` A/B stack.
+      **NOTE**: This code is *DEPRECATED* and will be removed Jun 1
+      2018.
 * `contrib/`
     + Contains patches needed in other projects for interoperability with AVB.
       For example, `contrib/linux/4.4` has the patches for Linux kernel 4.4,
@@ -697,9 +701,9 @@ if (is_slot_is_marked_as_successful(slot->ab_suffix)) {
 For an HLOS where it's possible to roll back to a previous version,
 `stored_rollback_index[n]` should be set to the largest possible value
 allowing all bootable slots to boot. This approach is implemented in
-AVB's experimental A/B stack `libavb_ab`, see the `avb_ab_flow()`
-implementation. Note that this requires verifying *all* bootable slots
-at every boot and this may impact boot time.
+AVB's experimental (and now deprecated) A/B stack `libavb_ab`, see the
+`avb_ab_flow()` implementation. Note that this requires verifying
+*all* bootable slots at every boot and this may impact boot time.
 
 ## Recommended Bootflow
 
diff --git a/boot_control/boot_control_avb.c b/boot_control/boot_control_avb.c
index f0e89d2..4a7cecf 100644
--- a/boot_control/boot_control_avb.c
+++ b/boot_control/boot_control_avb.c
@@ -29,6 +29,7 @@
 #include <hardware/boot_control.h>
 #include <hardware/hardware.h>
 
+#include <libavb_ab/libavb_ab.h>
 #include <libavb_user/libavb_user.h>
 
 static AvbOps* ops = NULL;
diff --git a/examples/uefi/Makefile b/examples/uefi/Makefile
index e19a273..95e7394 100644
--- a/examples/uefi/Makefile
+++ b/examples/uefi/Makefile
@@ -62,7 +62,9 @@ EFI_TARGET      = avb_bootloader.efi
 EFI_SHARED_OBJ  = $(patsubst %.efi,%.so,$(EFI_TARGET))
 
 EFI_CFLAGS = \
-    -DAVB_COMPILATION -DAVB_ENABLE_DEBUG -std=gnu99 \
+    -DAVB_COMPILATION -DAVB_ENABLE_DEBUG \
+    -DAVB_AB_I_UNDERSTAND_LIBAVB_AB_IS_DEPRECATED \
+    -std=gnu99 \
 	-I$(ANDROID_BUILD_TOP)/system/core/mkbootimg/ \
     -I$(AVB) \
     -I$(GNUEFI) \
diff --git a/libavb_ab/libavb_ab.h b/libavb_ab/libavb_ab.h
index 0dcf3e9..654ff5e 100644
--- a/libavb_ab/libavb_ab.h
+++ b/libavb_ab/libavb_ab.h
@@ -27,6 +27,17 @@
 
 #include <libavb/libavb.h>
 
+/* The libavb_ab/ and boot_control/ code has been marked for some time
+ * as experimental in anticipation of being removed in the future. It
+ * is now deprecated and to continue using it you must define
+ * AVB_AB_I_UNDERSTAND_LIBAVB_AB_IS_DEPRECATED. It will be removed Jun
+ * 1 2018.
+ */
+#ifndef AVB_AB_I_UNDERSTAND_LIBAVB_AB_IS_DEPRECATED
+#error \
+    "You must define AVB_AB_I_UNDERSTAND_LIBAVB_AB_IS_DEPRECATED to use this library."
+#endif
+
 /* The AVB_INSIDE_LIBAVB_AB_H preprocessor symbol is used to enforce
  * library users to include only this file. All public interfaces, and
  * only public interfaces, must be included here.
diff --git a/libavb_user/libavb_user.h b/libavb_user/libavb_user.h
index a8b8c55..a712f9a 100644
--- a/libavb_user/libavb_user.h
+++ b/libavb_user/libavb_user.h
@@ -25,7 +25,7 @@
 #ifndef LIBAVB_USER_H_
 #define LIBAVB_USER_H_
 
-#include <libavb_ab/libavb_ab.h>
+#include <libavb/libavb.h>
 
 /* The AVB_INSIDE_LIBAVB_USER_H preprocessor symbol is used to enforce
  * library users to include only this file. All public interfaces, and