diff --git a/mos.yml b/mos.yml
index 7d067d6..77a21ad 100644
--- a/mos.yml
+++ b/mos.yml
@@ -28,6 +28,11 @@ cdefs:
 config_schema:
   - ["debug.mbedtls_level", "i", 1, {title: "mbedTLS debug level"}]
 
+build_vars:
+  # Override to 0 to disable ATECCx08 support.
+  # Since library is binary, you also need to specify variant: noatca.
+  MGOS_MBEDTLS_ENABLE_ATCA: 1
+
 conds:
   # On CC3200 we use SimpleLink for SSL due to lack of space.
   # mbedTLS is still used for crypto primitives (e.g. GCP auth).
@@ -36,10 +41,11 @@ conds:
       cdefs:
         MG_ENABLE_SSL: 1
         MG_SSL_IF: MG_SSL_IF_MBEDTLS
-        MBEDTLS_AES_ATCA: 1
-        MBEDTLS_ECP_ATCA: 1
-      libs:
-        - origin: https://github.com/mongoose-os-libs/atca
+
+  - when: mos.platform == "cc3200"
+    apply:
+      build_vars:
+        MGOS_MBEDTLS_ENABLE_ATCA: 0
 
   - when: mos.platform == "cc3200"
     apply:
@@ -54,6 +60,14 @@ conds:
       includes:
         - include/cc32xx
 
+  - when: build_vars.MGOS_MBEDTLS_ENABLE_ATCA == "1"
+    apply:
+      libs:
+        - origin: https://github.com/mongoose-os-libs/atca
+      cdefs:
+        MBEDTLS_AES_ATCA: 1
+        MBEDTLS_ECP_ATCA: 1
+
 tags:
   - c
   - security