diff --git a/src/runtime/internal/atomic/atomic_s390x.go b/src/runtime/internal/atomic/atomic_s390x.go
index ec294a2..2ffbec0 100644
--- a/src/runtime/internal/atomic/atomic_s390x.go
+++ b/src/runtime/internal/atomic/atomic_s390x.go
@@ -42,11 +42,14 @@
 	*ptr = val
 }
 
+//go:notinheap
+type noWB struct{}
+
 // NO go:noescape annotation; see atomic_pointer.go.
 //go:noinline
 //go:nosplit
 func StorepNoWB(ptr unsafe.Pointer, val unsafe.Pointer) {
-	*(*uintptr)(ptr) = uintptr(val)
+	*(**noWB)(ptr) = (*noWB)(val)
 }
 
 //go:noinline