diff --git a/src/runtime/stack.go b/src/runtime/stack.go
index c572f7296f9..d971e5e26f8 100644
--- a/src/runtime/stack.go
+++ b/src/runtime/stack.go
@@ -112,7 +112,7 @@ const (
 	stackDebug       = 0
 	stackFromSystem  = 0 // allocate stacks from system memory instead of the heap
 	stackFaultOnFree = 0 // old stacks are mapped noaccess to detect use after free
-	stackPoisonCopy  = 1 // fill stack that should not be accessed with garbage, to detect bad dereferences during copy
+	stackPoisonCopy  = 0 // fill stack that should not be accessed with garbage, to detect bad dereferences during copy
 	stackNoCache     = 0 // disable per-P small stack caches
 
 	// check the BP links during traceback.