diff --git a/cheevos.c b/cheevos.c
index 53da6c4761..96bbbb84a3 100644
--- a/cheevos.c
+++ b/cheevos.c
@@ -1301,13 +1301,13 @@ int cheevos_get_by_content( const char** json, const void* data, size_t size )
 
    game_id = cheevos_get_game_id( hash );
 
-   if ( !game_id )
+   if ( !game_id && size < CHEEVOS_EIGHT_MB )
    {
-      /* If the content is a SNES game, continue MD5 with zeroes. */
+      /* Maybe the content is a SNES game, continue MD5 with zeroes up to 8MB. */
       size = CHEEVOS_EIGHT_MB - size;
       memset( (void*)buffer, 0, sizeof( buffer ) );
 
-      while ( size )
+      do
       {
          len = sizeof( buffer );
 
@@ -1316,7 +1316,7 @@ int cheevos_get_by_content( const char** json, const void* data, size_t size )
 
          MD5_Update( &saved_ctx, (void*)buffer, len );
          size -= len;
-      }
+      }while(size);
 
       MD5_Final( hash, &saved_ctx );