diff --git a/src/runtime/hashmap_fast.go b/src/runtime/hashmap_fast.go
index c378647892..f117311439 100644
--- a/src/runtime/hashmap_fast.go
+++ b/src/runtime/hashmap_fast.go
@@ -754,7 +754,8 @@ search:
 			if k.str != key.str && !memequal(k.str, key.str, uintptr(key.len)) {
 				continue
 			}
-			*(*string)(kptr) = ""
+			// Clear key's pointer.
+			k.str = nil
 			// Only clear value if there are pointers in it.
 			if t.elem.kind&kindNoPointers == 0 {
 				v := add(unsafe.Pointer(b), dataOffset+bucketCnt*2*sys.PtrSize+i*uintptr(t.valuesize))