diff --git a/src/reflect/type.go b/src/reflect/type.go
index d60d0b060b..1c30608cef 100644
--- a/src/reflect/type.go
+++ b/src/reflect/type.go
@@ -820,6 +820,9 @@ func (t *rtype) NumMethod() int {
 		tt := (*interfaceType)(unsafe.Pointer(t))
 		return tt.NumMethod()
 	}
+	if t.tflag&tflagUncommon == 0 {
+		return 0 // avoid methodCache lock in zero case
+	}
 	return len(t.exportedMethods())
 }