diff --git a/features/mbedtls/inc/mbedtls/config-no-entropy.h b/features/mbedtls/inc/mbedtls/config-no-entropy.h
index 7d34ad52ec..a0e979f0c2 100644
--- a/features/mbedtls/inc/mbedtls/config-no-entropy.h
+++ b/features/mbedtls/inc/mbedtls/config-no-entropy.h
@@ -82,7 +82,7 @@
 #define MBEDTLS_X509_USE_C
 #define MBEDTLS_X509_CRT_PARSE_C
 #define MBEDTLS_X509_CRL_PARSE_C
-//#define MBEDTLS_CMAC_C
+#define MBEDTLS_CMAC_C
 
 /* Miscellaneous options */
 #define MBEDTLS_AES_ROM_TABLES
diff --git a/features/mbedtls/inc/mbedtls/config.h b/features/mbedtls/inc/mbedtls/config.h
index 75b3245bd3..4a1d7f398b 100644
--- a/features/mbedtls/inc/mbedtls/config.h
+++ b/features/mbedtls/inc/mbedtls/config.h
@@ -1957,7 +1957,7 @@
  * Requires: MBEDTLS_AES_C or MBEDTLS_DES_C
  *
  */
-//#define MBEDTLS_CMAC_C
+#define MBEDTLS_CMAC_C
 
 /**
  * \def MBEDTLS_CTR_DRBG_C