diff --git a/server/registry.c b/server/registry.c
index fc29a8fc71d..34c962b8b0d 100644
--- a/server/registry.c
+++ b/server/registry.c
@@ -656,6 +656,7 @@ static struct key *create_key( struct key *key, const struct unicode_str *name,
     if (class && class->len)
     {
         key->classlen = class->len;
+        if (key->class) free(key->class);
         if (!(key->class = memdup( class->str, key->classlen ))) key->classlen = 0;
     }
     grab_object( key );