diff --git a/library/pkparse.c b/library/pkparse.c
index 4cff8d7..f567b17 100644
--- a/library/pkparse.c
+++ b/library/pkparse.c
@@ -309,7 +309,7 @@
         return( ret );
 
     if( len != MBEDTLS_OID_SIZE( MBEDTLS_OID_ANSI_X9_62_PRIME_FIELD ) ||
-        memcmp( p, MBEDTLS_OID_ANSI_X9_62_PRIME_FIELD, len ) != 0 )
+        mbedtls_platform_memcmp( p, MBEDTLS_OID_ANSI_X9_62_PRIME_FIELD, len ) != 0 )
     {
         return( MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE );
     }