diff --git a/src/runtime/mbarrier.go b/src/runtime/mbarrier.go
index 637d9b886a..bf75934ed6 100644
--- a/src/runtime/mbarrier.go
+++ b/src/runtime/mbarrier.go
@@ -145,7 +145,7 @@ func writebarrierptr(dst *uintptr, src uintptr) {
 	if !writeBarrier.needed {
 		return
 	}
-	if src != 0 && (src < sys.PhysPageSize || src == poisonStack) {
+	if src != 0 && src < sys.PhysPageSize {
 		systemstack(func() {
 			print("runtime: writebarrierptr *", dst, " = ", hex(src), "\n")
 			throw("bad pointer in write barrier")
@@ -164,7 +164,7 @@ func writebarrierptr_nostore(dst *uintptr, src uintptr) {
 	if !writeBarrier.needed {
 		return
 	}
-	if src != 0 && (src < sys.PhysPageSize || src == poisonStack) {
+	if src != 0 && src < sys.PhysPageSize {
 		systemstack(func() { throw("bad pointer in write barrier") })
 	}
 	writebarrierptr_nostore1(dst, src)
diff --git a/src/runtime/stack.go b/src/runtime/stack.go
index ee2797e144..b14b4005d8 100644
--- a/src/runtime/stack.go
+++ b/src/runtime/stack.go
@@ -127,7 +127,6 @@ const (
 
 const (
 	uintptrMask = 1<<(8*sys.PtrSize) - 1
-	poisonStack = uintptrMask & 0x6868686868686868
 
 	// Goroutine preemption request.
 	// Stored into g->stackguard0 to cause split stack check failure.
@@ -594,7 +593,7 @@ func adjustpointers(scanp unsafe.Pointer, cbv *bitvector, adjinfo *adjustinfo, f
 			pp := (*uintptr)(add(scanp, i*sys.PtrSize))
 		retry:
 			p := *pp
-			if f != nil && 0 < p && p < _PageSize && debug.invalidptr != 0 || p == poisonStack {
+			if f != nil && 0 < p && p < _PageSize && debug.invalidptr != 0 {
 				// Looks like a junk value in a pointer slot.
 				// Live analysis wrong?
 				getg().m.traceback = 2