diff --git a/src/harness/unittests/tsserverProjectSystem.ts b/src/harness/unittests/tsserverProjectSystem.ts
index d98c950988d..2a11e885f64 100644
--- a/src/harness/unittests/tsserverProjectSystem.ts
+++ b/src/harness/unittests/tsserverProjectSystem.ts
@@ -1,4 +1,4 @@
-/// <reference path="..\harness.ts" />
+/// <reference path="..\harness.ts" />
 /// <reference path="../../server/typingsInstaller/typingsInstaller.ts" />
 
 namespace ts.projectSystem {
@@ -137,6 +137,19 @@ namespace ts.projectSystem {
         return map(fileNames, toExternalFile);
     }
 
+    export class TestServerEventManager {
+        private events: server.ProjectServiceEvent[] = [];
+
+        handler: server.ProjectServiceEventHandler = (event: server.ProjectServiceEvent) => {
+            this.events.push(event);
+        }
+
+        checkEventCountOfType(eventType: "context" | "configFileDiag", expectedCount: number) {
+            const eventsOfType = filter(this.events, e => e.eventName === eventType);
+            assert.equal(eventsOfType.length, expectedCount, `The actual event counts of type ${eventType} is ${eventsOfType.length}, while expected ${expectedCount}`);
+        }
+    }
+
     export interface TestServerHostCreationParameters {
         useCaseSensitiveFileNames?: boolean;
         executingFilePath?: string;
@@ -160,11 +173,11 @@ namespace ts.projectSystem {
         return host;
     }
 
-    export function createSession(host: server.ServerHost, typingsInstaller?: server.ITypingsInstaller) {
+    export function createSession(host: server.ServerHost, typingsInstaller?: server.ITypingsInstaller, projectServiceEventHandler?: server.ProjectServiceEventHandler) {
         if (typingsInstaller === undefined) {
             typingsInstaller = new TestTypingsInstaller("/a/data/", /*throttleLimit*/5, host);
         }
-        return new server.Session(host, nullCancellationToken, /*useSingleInferredProject*/ false, typingsInstaller, Utils.byteLength, process.hrtime, nullLogger, /*canUseEvents*/ false);
+        return new server.Session(host, nullCancellationToken, /*useSingleInferredProject*/ false, typingsInstaller, Utils.byteLength, process.hrtime, nullLogger, /*canUseEvents*/ projectServiceEventHandler !== undefined, projectServiceEventHandler);
     }
 
     export interface CreateProjectServiceParameters {
@@ -2065,4 +2078,92 @@ namespace ts.projectSystem {
             assert.equal(snap.getLength(), expectedLength, "Incorrect snapshot size");
         }
     });
+
+    describe("Configure file diagnostics events", () => {
+
+        it("are generated when the config file has errors", () => {
+            const serverEventManager = new TestServerEventManager();
+            const file = {
+                path: "/a/b/app.ts",
+                content: "let x = 10"
+            };
+            const configFile = {
+                path: "/a/b/tsconfig.json",
+                content: `{
+                    "compilerOptions": {
+                        "foo": "bar",
+                        "allowJS": true
+                    }
+                }`
+            };
+
+            const host = createServerHost([file, configFile]);
+            const session = createSession(host, /*typingsInstaller*/ undefined, serverEventManager.handler);
+            openFilesForSession([file], session);
+            serverEventManager.checkEventCountOfType("configFileDiag", 1);
+        });
+
+        it("are generated when the config file doesn't have errors", () => {
+            const serverEventManager = new TestServerEventManager();
+            const file = {
+                path: "/a/b/app.ts",
+                content: "let x = 10"
+            };
+            const configFile = {
+                path: "/a/b/tsconfig.json",
+                content: `{
+                    "compilerOptions": {}
+                }`
+            };
+
+            const host = createServerHost([file, configFile]);
+            const session = createSession(host, /*typingsInstaller*/ undefined, serverEventManager.handler);
+            openFilesForSession([file], session);
+            serverEventManager.checkEventCountOfType("configFileDiag", 1);
+        });
+    });
+
+    describe("Configure file diagnostics events", () => {
+
+        it("are generated when the config file has errors", () => {
+            const serverEventManager = new TestServerEventManager();
+            const file = {
+                path: "/a/b/app.ts",
+                content: "let x = 10"
+            };
+            const configFile = {
+                path: "/a/b/tsconfig.json",
+                content: `{
+                    "compilerOptions": {
+                        "foo": "bar",
+                        "allowJS": true
+                    }
+                }`
+            };
+
+            const host = createServerHost([file, configFile]);
+            const session = createSession(host, /*typingsInstaller*/ undefined, serverEventManager.handler);
+            openFilesForSession([file], session);
+            serverEventManager.checkEventCountOfType("configFileDiag", 1);
+        });
+
+        it("are generated when the config file doesn't have errors", () => {
+            const serverEventManager = new TestServerEventManager();
+            const file = {
+                path: "/a/b/app.ts",
+                content: "let x = 10"
+            };
+            const configFile = {
+                path: "/a/b/tsconfig.json",
+                content: `{
+                    "compilerOptions": {}
+                }`
+            };
+
+            const host = createServerHost([file, configFile]);
+            const session = createSession(host, /*typingsInstaller*/ undefined, serverEventManager.handler);
+            openFilesForSession([file], session);
+            serverEventManager.checkEventCountOfType("configFileDiag", 1);
+        });
+    });
 }
\ No newline at end of file
diff --git a/src/server/editorServices.ts b/src/server/editorServices.ts
index d58bb416f26..e10b7e8b2cf 100644
--- a/src/server/editorServices.ts
+++ b/src/server/editorServices.ts
@@ -754,12 +754,14 @@ namespace ts.server {
         }
 
         private reportConfigFileDiagnostics(configFileName: string, diagnostics: Diagnostic[], triggerFile?: string) {
-            if (diagnostics && diagnostics.length > 0) {
-                this.eventHandler({
-                    eventName: "configFileDiag",
-                    data: { configFileName, diagnostics, triggerFile }
-                });
+            if (!this.eventHandler) {
+                return;
             }
+
+            this.eventHandler({
+                eventName: "configFileDiag",
+                data: { configFileName, diagnostics: diagnostics || [], triggerFile }
+            });
         }
 
         private createAndAddConfiguredProject(configFileName: NormalizedPath, projectOptions: ProjectOptions, configFileErrors: Diagnostic[], clientFileName?: string) {
diff --git a/src/server/session.ts b/src/server/session.ts
index ff0de939d9d..9ab2a2c0ec9 100644
--- a/src/server/session.ts
+++ b/src/server/session.ts
@@ -155,6 +155,8 @@ namespace ts.server {
         private immediateId: any;
         private changeSeq = 0;
 
+        private eventHander: ProjectServiceEventHandler;
+
         constructor(
             private host: ServerHost,
             cancellationToken: HostCancellationToken,
@@ -163,17 +165,18 @@ namespace ts.server {
             private byteLength: (buf: string, encoding?: string) => number,
             private hrtime: (start?: number[]) => number[],
             protected logger: Logger,
-            protected readonly canUseEvents: boolean) {
+            protected readonly canUseEvents: boolean,
+            eventHandler?: ProjectServiceEventHandler) {
 
-            const eventHandler: ProjectServiceEventHandler = canUseEvents
-                ? event => this.handleEvent(event)
+            this.eventHander = canUseEvents
+                ? eventHandler || (event => this.defaultEventHandler(event))
                 : undefined;
 
-            this.projectService = new ProjectService(host, logger, cancellationToken, useSingleInferredProject, typingsInstaller, eventHandler);
+            this.projectService = new ProjectService(host, logger, cancellationToken, useSingleInferredProject, typingsInstaller, this.eventHander);
             this.gcTimer = new GcTimer(host, /*delay*/ 7000, logger);
         }
 
-        private handleEvent(event: ProjectServiceEvent) {
+        private defaultEventHandler(event: ProjectServiceEvent) {
             switch (event.eventName) {
                 case "context":
                     const { project, fileName } = event.data;
@@ -714,8 +717,11 @@ namespace ts.server {
          */
         private openClientFile(fileName: NormalizedPath, fileContent?: string, scriptKind?: ScriptKind) {
             const { configFileName, configFileErrors } = this.projectService.openClientFileWithNormalizedPath(fileName, fileContent, scriptKind);
-            if (configFileErrors) {
-                this.configFileDiagnosticEvent(fileName, configFileName, configFileErrors);
+            if (this.eventHander) {
+                this.eventHander({
+                    eventName: "configFileDiag",
+                    data: { fileName, configFileName, diagnostics: configFileErrors || [] }
+                });
             }
         }