diff --git a/racket/src/racket/gc2/block_cache.c b/racket/src/racket/gc2/block_cache.c
index 3fe21f4e1b..299fe4b14f 100644
--- a/racket/src/racket/gc2/block_cache.c
+++ b/racket/src/racket/gc2/block_cache.c
@@ -97,7 +97,7 @@ static block_desc *bc_alloc_std_block(block_group *bg) {
     bg->block_size <<= 1;
   }
 
-  bd = (block_desc*) ofm_malloc(sizeof(block_desc));
+  bd = (block_desc*) ofm_malloc_zero(sizeof(block_desc));
   if (!bd) {
     os_free_pages(r, this_block_size);
     return NULL;
diff --git a/racket/src/racket/src/validate.c b/racket/src/racket/src/validate.c
index ed3bf42350..1d1cd7cbf0 100644
--- a/racket/src/racket/src/validate.c
+++ b/racket/src/racket/src/validate.c
@@ -414,7 +414,7 @@ static int define_values_validate(Scheme_Object *data, Mz_CPort *port,
   result = validate_expr(port, val, stack, tls, 
                          depth, letlimit, delta, 
                          num_toplevels, num_stxes, num_lifts, tl_use_map,
-                         tl_state, tl_timestamp + (stinfo.uses_super ? 1 : 0),
+                         tl_state, tl_timestamp + ((is_struct && stinfo.uses_super) ? 1 : 0),
                          NULL, !!only_var, 0, vc, 0, 0, NULL,
                          size-1, _st_ht);