diff --git a/library/asn1write.c b/library/asn1write.c
index e393ef8..fe10e21 100644
--- a/library/asn1write.c
+++ b/library/asn1write.c
@@ -348,7 +348,7 @@
     while( list != NULL )
     {
         if( list->oid.len == len &&
-            mbedtls_platform_memcmp( list->oid.p, oid, len ) == 0 )
+            mbedtls_platform_memequal( list->oid.p, oid, len ) == 0 )
         {
             break;
         }