diff --git a/library/rsa.c b/library/rsa.c
index 6526978e2..7075f131f 100644
--- a/library/rsa.c
+++ b/library/rsa.c
@@ -75,6 +75,7 @@ static void mbedtls_zeroize( void *v, size_t n ) {
     volatile unsigned char *p = (unsigned char*)v; while( n-- ) *p++ = 0;
 }
 
+#if defined(MBEDTLS_PKCS1_V15)
 /* constant-time buffer comparison */
 static inline int mbedtls_safer_memcmp( const void *a, const void *b, size_t n )
 {
@@ -88,6 +89,7 @@ static inline int mbedtls_safer_memcmp( const void *a, const void *b, size_t n )
 
     return( diff );
 }
+#endif /* MBEDTLS_PKCS1_V15 */
 
 int mbedtls_rsa_import( mbedtls_rsa_context *ctx,
                         const mbedtls_mpi *N,
diff --git a/tests/suites/test_suite_rsa.function b/tests/suites/test_suite_rsa.function
index 953c6338f..fd632dad6 100644
--- a/tests/suites/test_suite_rsa.function
+++ b/tests/suites/test_suite_rsa.function
@@ -122,7 +122,6 @@ void rsa_pkcs1_sign_raw( char *message_hex_string, char *hash_result_string,
                          char *input_N, int radix_E, char *input_E,
                          char *result_hex_str )
 {
-    int res;
     unsigned char message_str[1000];
     unsigned char hash_result[1000];
     unsigned char output[1000];
@@ -167,6 +166,7 @@ void rsa_pkcs1_sign_raw( char *message_hex_string, char *hash_result_string,
     /* For PKCS#1 v1.5, there is an alternative way to generate signatures */
     if( padding_mode == MBEDTLS_RSA_PKCS_V15 )
     {
+        int res;
         memset( output, 0x00, 1000 );
         memset( output_str, 0x00, 1000 );
 
@@ -203,7 +203,6 @@ void rsa_pkcs1_verify_raw( char *message_hex_string, char *hash_result_string,
                            char *input_N, int radix_E, char *input_E,
                            char *result_hex_str, int correct )
 {
-    int res;
     unsigned char message_str[1000];
     unsigned char hash_result[1000];
     unsigned char result_str[1000];
@@ -240,6 +239,7 @@ void rsa_pkcs1_verify_raw( char *message_hex_string, char *hash_result_string,
     /* For PKCS#1 v1.5, there is an alternative way to verify signatures */
     if( padding_mode == MBEDTLS_RSA_PKCS_V15 )
     {
+        int res;
         int ok;
         size_t olen;