diff --git a/src/server/editorServices.ts b/src/server/editorServices.ts
index 857d2c95dc5..5dd6865f568 100644
--- a/src/server/editorServices.ts
+++ b/src/server/editorServices.ts
@@ -167,7 +167,7 @@ namespace ts.server {
                 return undefined;
             }
             if (isInferredProjectName(projectName)) {
-                return forEach(this.inferredProjects, p => p.getProjectName() === projectName && p);
+                return findProjectByName(projectName, this.inferredProjects);
             }
             return this.findExternalProjectByProjectName(projectName) || this.findConfiguredProjectByProjectName(toNormalizedPath(projectName));
         }
@@ -209,17 +209,19 @@ namespace ts.server {
 
                 info.detachAllProjects();
 
+                if (!this.eventHandler) {
+                    return;
+                }
+
                 for (const openFile of this.openFileRoots) {
-                    if (this.eventHandler) {
-                        this.eventHandler("context", openFile.getDefaultProject(), openFile.fileName);
-                    }
+                    this.eventHandler("context", openFile.getDefaultProject(), openFile.fileName);
                 }
 
                 for (const openFile of this.openFilesReferenced) {
-                    if (this.eventHandler) {
-                        this.eventHandler("context", openFile.getDefaultProject(), openFile.fileName);
-                    }
+                    this.eventHandler("context", openFile.getDefaultProject(), openFile.fileName);
                 }
+                
+                // TODO: project system view is inconsistent
             }
 
             this.printProjects();
diff --git a/src/server/lsHost.ts b/src/server/lsHost.ts
index b65c71d5e28..36bdc7a9afe 100644
--- a/src/server/lsHost.ts
+++ b/src/server/lsHost.ts
@@ -89,8 +89,8 @@ namespace ts.server {
         }
 
         getDefaultLibFileName() {
-            const nodeModuleBinDir = ts.getDirectoryPath(ts.normalizePath(this.host.getExecutingFilePath()));
-            return ts.combinePaths(nodeModuleBinDir, ts.getDefaultLibFileName(this.compilationSettings));
+            const nodeModuleBinDir = getDirectoryPath(normalizePath(this.host.getExecutingFilePath()));
+            return combinePaths(nodeModuleBinDir, getDefaultLibFileName(this.compilationSettings));
         }
 
         getScriptSnapshot(filename: string): ts.IScriptSnapshot {
diff --git a/src/server/project.ts b/src/server/project.ts
index 00eeda9d8f0..40bd98c980b 100644
--- a/src/server/project.ts
+++ b/src/server/project.ts
@@ -19,8 +19,8 @@ namespace ts.server {
     }
 
     export abstract class Project {
-        private readonly rootFiles: ScriptInfo[] = [];
-        private readonly rootFilesMap: FileMap<ScriptInfo> = createFileMap<ScriptInfo>();
+        private rootFiles: ScriptInfo[] = [];
+        private rootFilesMap: FileMap<ScriptInfo> = createFileMap<ScriptInfo>();
         private lsHost: ServerLanguageServiceHost;
         private program: ts.Program;
 
@@ -96,11 +96,24 @@ namespace ts.server {
         abstract getProjectName(): string;
 
         close() {
-            for (const fileName of this.getFileNames()) {
-                const info = this.projectService.getScriptInfoForNormalizedPath(fileName);
-                info.detachFromProject(this);
+            if (this.program) {
+                // if we have a program - release all files that are enlisted in program
+                for (const f of this.program.getSourceFiles()) {
+                    const info = this.projectService.getScriptInfo(f.fileName);
+                    info.detachFromProject(this);
+                }
             }
-            // signal language service to release files acquired from document registry
+            else {
+                // release all root files
+                for (const root of this.rootFiles) {
+                    root.detachFromProject(this);
+                }
+            }
+            this.rootFiles = undefined;
+            this.rootFilesMap = undefined;
+            this.program = undefined;
+
+            // signal language service to release source files acquired from document registry
             this.languageService.dispose();
         }
 
@@ -137,7 +150,7 @@ namespace ts.server {
         }
 
         containsScriptInfo(info: ScriptInfo): boolean {
-            return this.program && this.program.getSourceFileByPath(info.path) !== undefined;
+            return this.isRoot(info) || (this.program && this.program.getSourceFileByPath(info.path) !== undefined);
         }
 
         containsFile(filename: NormalizedPath, requireOpen?: boolean) {
diff --git a/tests/cases/unittests/tsserverProjectSystem.ts b/tests/cases/unittests/tsserverProjectSystem.ts
index 9e003bc8049..bcdcdc09106 100644
--- a/tests/cases/unittests/tsserverProjectSystem.ts
+++ b/tests/cases/unittests/tsserverProjectSystem.ts
@@ -698,5 +698,28 @@ namespace ts {
             checkNumberOfInferredProjects(projectService, 1);
             checkProjectActualFiles(projectService.inferredProjects[0], [file2.path, file3.path, libFile.path]);
         });
+
+        it ("should close configured project after closing last open file", () => {
+            const file1 = {
+                path: "/a/b/main.ts",
+                content: "let x =1;"
+            };
+            const configFile: FileOrFolder = {
+                path: "/a/b/tsconfig.json",
+                content: `{
+                    "compilerOptions": {
+                        "target": "es6"
+                    }, 
+                    "files": [ "main.ts" ]
+                }`
+            };
+            const host = createServerHost({ fileOrFolderList: [file1, configFile, libFile], libFile });
+            const projectService = new server.ProjectService(host, nullLogger, nullCancellationToken, /*useOneInferredProject*/ true);
+            projectService.openClientFile(file1.path);
+            checkNumberOfConfiguredProjects(projectService, 1);
+
+            projectService.closeClientFile(file1.path);
+            checkNumberOfConfiguredProjects(projectService, 0);
+        }) 
     });
 }
\ No newline at end of file