diff --git a/packages/grpc-native-core/src/credentials.js b/packages/grpc-native-core/src/credentials.js
index 3c05329e..5a9dbfd4 100644
--- a/packages/grpc-native-core/src/credentials.js
+++ b/packages/grpc-native-core/src/credentials.js
@@ -184,6 +184,30 @@ exports.createFromMetadataGenerator = function(metadata_generator) {
   });
 };
 
+function getAuthorizationHeaderFromGoogleCredential(google_credential, url, callback) {
+  // google-auth-library pre-v2.0.0 does not have getRequestHeaders
+  // but has getRequestMetadata, which is deprecated in v2.0.0
+  if (typeof google_credential.getRequestHeaders === 'function') {
+    google_credential.getRequestHeaders(url)
+      .then(function(header) {
+        callback(null, header.Authorization);
+      })
+      .catch(function(err) {
+        callback(err);
+        return;
+      });
+  }
+  else {
+    google_credential.getRequestMetadata(url, function(err, header) {
+      if (err) {
+        callback(err);
+        return;
+      }
+      callback(null, header.Authorization);
+    });
+  }
+}
+
 /**
  * Create a gRPC credential from a Google credential object.
  * @memberof grpc.credentials
@@ -195,16 +219,16 @@ exports.createFromMetadataGenerator = function(metadata_generator) {
 exports.createFromGoogleCredential = function(google_credential) {
   return exports.createFromMetadataGenerator(function(auth_context, callback) {
     var service_url = auth_context.service_url;
-    google_credential.getRequestHeaders(service_url)
-      .then(function(header) {
+    getAuthorizationHeaderFromGoogleCredential(google_credential, service_url,
+      function(err, authHeader) {
+        if (err) {
+          common.log(constants.logVerbosity.INFO, 'Auth error:' + err);
+          callback(err);
+          return;
+        }
         var metadata = new Metadata();
-        metadata.add('authorization', header.Authorization);
+        metadata.add('authorization', authHeader);
         callback(null, metadata);
-      })
-      .catch(function(err) {
-        common.log(constants.logVerbosity.INFO, 'Auth error:' + err);
-        callback(err);
-        return;
       });
   });
 };