diff --git a/client/util.go b/client/util.go
new file mode 100644
index 000000000..fc0800b3d
--- /dev/null
+++ b/client/util.go
@@ -0,0 +1,23 @@
+// Copyright 2016 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package client
+
+// IsKeyNotFound returns true if the error code is ErrorCodeKeyNotFound.
+func IsKeyNotFound(err error) bool {
+	if cErr, ok := err.(Error); ok {
+		return cErr.Code == ErrorCodeKeyNotFound
+	}
+	return false
+}