diff --git a/include/mbedtls/aes.h b/include/mbedtls/aes.h
index 62c1f92..cfb20c4 100644
--- a/include/mbedtls/aes.h
+++ b/include/mbedtls/aes.h
@@ -67,22 +67,6 @@
 /* MBEDTLS_ERR_AES_HW_ACCEL_FAILED is deprecated and should not be used. */
 #define MBEDTLS_ERR_AES_HW_ACCEL_FAILED                   -0x0025  /**< AES hardware accelerator failed. */
 
-#if defined( MBEDTLS_CHECK_PARAMS )
-#define MBEDTLS_AES_VALIDATE_RET( cond )  do{ if( !(cond)  ) {                 \
-                                            MBEDTLS_PARAM_FAILED( #cond );      \
-                                            return MBEDTLS_ERR_AES_BAD_INPUT_DATA;} \
-                                          } while(0);
-
-#define MBEDTLS_AES_VALIDATE( cond )      do{ if( !(cond)  ) {                 \
-                                            MBEDTLS_PARAM_FAILED( #cond );     \
-                                            return; }                          \
-                                          } while(0);
-#else
-/* No validation of parameters will be performed */
-#define MBEDTLS_AES_VALIDATE_RET( cond )
-#define MBEDTLS_AES_VALIDATE( cond)
-#endif
-
 #if ( defined(__ARMCC_VERSION) || defined(_MSC_VER) ) && \
     !defined(inline) && !defined(__cplusplus)
 #define inline __inline
diff --git a/include/mbedtls/platform_util.h b/include/mbedtls/platform_util.h
index ed21ffa..1ac16d4 100644
--- a/include/mbedtls/platform_util.h
+++ b/include/mbedtls/platform_util.h
@@ -81,6 +81,33 @@
                            const char *file,
                            int line );
 #endif /* MBEDTLS_PARAM_FAILED */
+
+/* Internal macro meant to be called only from within the library. */
+#define MBEDTLS_INTERNAL_VALIDATE_RET( cond, ret )  \
+    do {                                            \
+        if( !(cond) )                               \
+        {                                           \
+            MBEDTLS_PARAM_FAILED( #cond );          \
+            return( ret );                          \
+        }                                           \
+    } while( 0 )
+
+/* Internal macro meant to be called only from within the library. */
+#define MBEDTLS_INTERNAL_VALIDATE( cond )           \
+    do {                                            \
+        if( !(cond) )                               \
+        {                                           \
+            MBEDTLS_PARAM_FAILED( #cond );          \
+            return;                                 \
+        }                                           \
+    } while( 0 )
+
+#else /* MBEDTLS_CHECK_PARAMS */
+
+/* Internal macros meant to be called only from within the library. */
+#define MBEDTLS_INTERNAL_VALIDATE_RET( cond, ret )  do { } while( 0 )
+#define MBEDTLS_INTERNAL_VALIDATE( cond )           do { } while( 0 )
+
 #endif /* MBEDTLS_CHECK_PARAMS */
 
 /**
diff --git a/library/aes.c b/library/aes.c
index 7a364a0..6ff39d7 100644
--- a/library/aes.c
+++ b/library/aes.c
@@ -56,6 +56,12 @@
 
 #if !defined(MBEDTLS_AES_ALT)
 
+/* Parameter validation macros based on platform_util.h */
+#define AES_VALIDATE_RET( cond )    \
+    MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_AES_BAD_INPUT_DATA)
+#define AES_VALIDATE( cond )        \
+    MBEDTLS_INTERNAL_VALIDATE( cond )
+
 /*
  * 32-bit integer manipulation macros (little endian)
  */
@@ -511,7 +517,7 @@
 
 void mbedtls_aes_init( mbedtls_aes_context *ctx )
 {
-    MBEDTLS_AES_VALIDATE( ctx != NULL );
+    AES_VALIDATE( ctx != NULL );
 
     memset( ctx, 0, sizeof( mbedtls_aes_context ) );
 }
@@ -527,7 +533,7 @@
 #if defined(MBEDTLS_CIPHER_MODE_XTS)
 void mbedtls_aes_xts_init( mbedtls_aes_xts_context *ctx )
 {
-    MBEDTLS_AES_VALIDATE( ctx != NULL );
+    AES_VALIDATE( ctx != NULL );
 
     mbedtls_aes_init( &ctx->crypt );
     mbedtls_aes_init( &ctx->tweak );
@@ -535,7 +541,7 @@
 
 void mbedtls_aes_xts_free( mbedtls_aes_xts_context *ctx )
 {
-    MBEDTLS_AES_VALIDATE( ctx != NULL );
+    AES_VALIDATE( ctx != NULL );
 
     mbedtls_aes_free( &ctx->crypt );
     mbedtls_aes_free( &ctx->tweak );
@@ -552,7 +558,7 @@
     unsigned int i;
     uint32_t *RK;
 
-    MBEDTLS_AES_VALIDATE_RET( ctx != NULL && key != NULL );
+    AES_VALIDATE_RET( ctx != NULL && key != NULL );
 
     switch( keybits )
     {
@@ -670,7 +676,7 @@
     uint32_t *RK;
     uint32_t *SK;
 
-    MBEDTLS_AES_VALIDATE_RET( ctx != NULL && key != NULL );
+    AES_VALIDATE_RET( ctx != NULL && key != NULL );
 
     mbedtls_aes_init( &cty );