diff --git a/package.json b/package.json
index cb324a08..5310e7f5 100644
--- a/package.json
+++ b/package.json
@@ -38,7 +38,7 @@
     "through2": "^2.0.3",
     "ts-node": "^3.3.0",
     "tslint": "^5.5.0",
-    "typescript": "^2.5.1",
+    "typescript": "~2.7.0",
     "xml2js": "^0.4.19"
   },
   "contributors": [
diff --git a/packages/grpc-js-core/package.json b/packages/grpc-js-core/package.json
index d5fdd46c..e0d48bd4 100644
--- a/packages/grpc-js-core/package.json
+++ b/packages/grpc-js-core/package.json
@@ -19,7 +19,7 @@
     "@types/node": "^8.0.55",
     "clang-format": "^1.0.55",
     "gts": "^0.5.1",
-    "typescript": "^2.6.1"
+    "typescript": "~2.7.0"
   },
   "contributors": [
     {
diff --git a/packages/grpc-js-core/src/channel.ts b/packages/grpc-js-core/src/channel.ts
index 35ca6f6c..51ec1fa5 100644
--- a/packages/grpc-js-core/src/channel.ts
+++ b/packages/grpc-js-core/src/channel.ts
@@ -76,7 +76,7 @@ export class Http2Channel extends EventEmitter implements Channel {
   private connectivityState: ConnectivityState = ConnectivityState.IDLE;
   /* For now, we have up to one subchannel, which will exist as long as we are
    * connecting or trying to connect */
-  private subChannel: http2.ClientHttp2Session|null;
+  private subChannel: http2.ClientHttp2Session|null = null;
   private filterStackFactory: FilterStackFactory;
 
   private subChannelConnectCallback: ()=>void = () => {};
@@ -123,7 +123,7 @@ export class Http2Channel extends EventEmitter implements Channel {
   }
 
   // Transition from any of a set of oldStates to a specific newState
-  private transitionToState(oldStates: [ConnectivityState], newState: ConnectivityState): void {
+  private transitionToState(oldStates: ConnectivityState[], newState: ConnectivityState): void {
     if (oldStates.indexOf(this.connectivityState) > -1) {
       let oldState: ConnectivityState = this.connectivityState;
       this.connectivityState = newState;
diff --git a/packages/grpc-js-core/test/test-call-stream.ts b/packages/grpc-js-core/test/test-call-stream.ts
index e7126d62..91d694dc 100644
--- a/packages/grpc-js-core/test/test-call-stream.ts
+++ b/packages/grpc-js-core/test/test-call-stream.ts
@@ -38,11 +38,11 @@ class ClientHttp2StreamMock extends stream.Duplex implements http2.ClientHttp2St
   }
   bytesRead = 0;
   dataFrame = 0;
-  aborted: boolean;
-  destroyed: boolean;
-  rstCode: number;
-  session: http2.Http2Session;
-  state: http2.StreamState;
+  aborted: boolean = false;
+  destroyed: boolean = false;
+  rstCode: number = 0;
+  session: http2.Http2Session = {} as any;
+  state: http2.StreamState = {} as any;
   priority = mockFunction;
   rstStream = mockFunction;
   rstWithNoError = mockFunction;
diff --git a/packages/grpc-js-core/test/test-channel-credentials.ts b/packages/grpc-js-core/test/test-channel-credentials.ts
index fac88110..15dfbfac 100644
--- a/packages/grpc-js-core/test/test-channel-credentials.ts
+++ b/packages/grpc-js-core/test/test-channel-credentials.ts
@@ -8,7 +8,7 @@ import {ChannelCredentials} from '../src/channel-credentials';
 import {assert2, mockFunction} from './common';
 
 class CallCredentialsMock implements CallCredentials {
-  child: CallCredentialsMock;
+  child: CallCredentialsMock|null = null;
   constructor(child?: CallCredentialsMock) {
     if (child) {
       this.child = child;
diff --git a/packages/grpc-js/package.json b/packages/grpc-js/package.json
index 1dbddbb0..8486c043 100644
--- a/packages/grpc-js/package.json
+++ b/packages/grpc-js/package.json
@@ -29,6 +29,6 @@
   },
   "devDependencies": {
     "gts": "^0.5.1",
-    "typescript": "^2.6.1"
+    "typescript": "~2.7.0"
   }
 }
diff --git a/packages/grpc-native-core/src/client.js b/packages/grpc-native-core/src/client.js
index 1c874e86..b9de0ab5 100644
--- a/packages/grpc-native-core/src/client.js
+++ b/packages/grpc-native-core/src/client.js
@@ -52,6 +52,22 @@ var Duplex = stream.Duplex;
 var util = require('util');
 var version = require('../package.json').version;
 
+/**
+ * Create an Error object from a status object
+ * @private
+ * @param {grpc~StatusObject} status The status object
+ * @return {Error} The resulting Error
+ */
+function createStatusError(status) {
+  let statusName = _.invert(constants.status)[status.code];
+  let message = `${status.code} ${statusName}: ${status.details}`;
+  let error = new Error(message);
+  error.code = status.code;
+  error.metadata = status.metadata;
+  error.details = status.details;
+  return error;
+}
+
 /**
  * Initial response metadata sent by the server when it starts processing the
  * call
@@ -251,9 +267,7 @@ function _emitStatusIfDone() {
     if (status.code === constants.status.OK) {
       this.push(null);
     } else {
-      var error = new Error(status.details);
-      error.code = status.code;
-      error.metadata = status.metadata;
+      var error = createStatusError(status);
       this.emit('error', error);
     }
     this.emit('status', status);
@@ -556,9 +570,7 @@ Client.prototype.makeUnaryRequest = function(method, serialize, deserialize,
       }
     }
     if (status.code !== constants.status.OK) {
-      error = new Error(status.details);
-      error.code = status.code;
-      error.metadata = status.metadata;
+      error = new createStatusError(status);
       callback(error);
     } else {
       callback(null, deserialized);
@@ -645,9 +657,7 @@ Client.prototype.makeClientStreamRequest = function(method, serialize,
       }
     }
     if (status.code !== constants.status.OK) {
-      error = new Error(response.status.details);
-      error.code = status.code;
-      error.metadata = status.metadata;
+      error = createStatusError(status);
       callback(error);
     } else {
       callback(null, deserialized);
diff --git a/test/api/credentials_test.js b/test/api/credentials_test.js
index 729a5a9c..f9bdefaf 100644
--- a/test/api/credentials_test.js
+++ b/test/api/credentials_test.js
@@ -319,7 +319,7 @@ describe('client credentials', function() {
                             client_options);
     client.unary({}, function(err, data) {
       assert(err);
-      assert.strictEqual(err.message,
+      assert.strictEqual(err.details,
                          'Getting metadata from plugin failed with error: ' +
                          'Authentication error');
       assert.notStrictEqual(err.code, grpc.status.OK);
@@ -369,7 +369,7 @@ describe('client credentials', function() {
                             client_options);
     client.unary({}, function(err, data) {
       assert(err);
-      assert.strictEqual(err.message,
+      assert.strictEqual(err.details,
                          'Getting metadata from plugin failed with error: ' +
                          'Authentication failure');
       done();
diff --git a/test/api/surface_test.js b/test/api/surface_test.js
index 5fdcbcfb..3bffaf8e 100644
--- a/test/api/surface_test.js
+++ b/test/api/surface_test.js
@@ -981,7 +981,7 @@ describe('Other conditions', function() {
       client.unary({error: true}, function(err, data) {
         assert(err);
         assert.strictEqual(err.code, grpc.status.UNKNOWN);
-        assert.strictEqual(err.message, 'Requested error');
+        assert.strictEqual(err.details, 'Requested error');
         done();
       });
     });
@@ -989,7 +989,7 @@ describe('Other conditions', function() {
       var call = client.clientStream(function(err, data) {
         assert(err);
         assert.strictEqual(err.code, grpc.status.UNKNOWN);
-        assert.strictEqual(err.message, 'Requested error');
+        assert.strictEqual(err.details, 'Requested error');
         done();
       });
       call.write({error: false});
@@ -1001,7 +1001,7 @@ describe('Other conditions', function() {
       call.on('data', function(){});
       call.on('error', function(error) {
         assert.strictEqual(error.code, grpc.status.UNKNOWN);
-        assert.strictEqual(error.message, 'Requested error');
+        assert.strictEqual(error.details, 'Requested error');
         done();
       });
     });
@@ -1013,7 +1013,7 @@ describe('Other conditions', function() {
       call.on('data', function(){});
       call.on('error', function(error) {
         assert.strictEqual(error.code, grpc.status.UNKNOWN);
-        assert.strictEqual(error.message, 'Requested error');
+        assert.strictEqual(error.details, 'Requested error');
         done();
       });
     });
diff --git a/test/interop/interop_client.js b/test/interop/interop_client.js
index 73b84c38..83890bca 100644
--- a/test/interop/interop_client.js
+++ b/test/interop/interop_client.js
@@ -347,7 +347,7 @@ function statusCodeAndMessage(client, done) {
   client.unaryCall(arg, function(err, resp) {
     assert(err);
     assert.strictEqual(err.code, 2);
-    assert.strictEqual(err.message, 'test status message');
+    assert.strictEqual(err.details, 'test status message');
     done();
   });
   var duplex = client.fullDuplexCall();