1 files changed, 3 insertions, 2 deletions
diff --git a/yarvcore.c b/yarvcore.c
index e4e93aa0e4..f5b3225a2f 100644
--- a/yarvcore.c
+++ b/yarvcore.c
@@ -327,9 +327,10 @@ th_init2(rb_thread_t *th)
     MEMZERO(th, rb_thread_t, 1);
 
     /* allocate thread stack */
-    th->stack = ALLOC_N(VALUE, RUBY_VM_THREAD_STACK_SIZE);
-
     th->stack_size = RUBY_VM_THREAD_STACK_SIZE;
+    th->stack = ALLOC_N(VALUE, th->stack_size);
+    MEMZERO(th->stack, VALUE, th->stack_size);
+
     th->cfp = (void *)(th->stack + th->stack_size);
     th->cfp--;