diff --git a/packages/grpc-native-core/src/client.js b/packages/grpc-native-core/src/client.js
index d1390742..0ae467ac 100644
--- a/packages/grpc-native-core/src/client.js
+++ b/packages/grpc-native-core/src/client.js
@@ -982,9 +982,13 @@ exports.getClientChannel = function(client) {
  * @returns {Object.<string, Interceptor[]>}
  */
 exports.getClientInterceptors = function(client) {
-  return _.mapValues(client.$method_definitions, function(def, name) {
-    return client[name].interceptors;
-  });
+  return Object.keys(client.$method_definitions)
+    .reduce((acc, key) => {
+      if (typeof key === 'string') {
+        acc[key] = client[key].interceptors;
+      }
+      return acc;
+    }, {});
 };
 
 /**