diff --git a/src/server/editorServices.ts b/src/server/editorServices.ts
index 7eabfc895f914..c46f3374ecc03 100644
--- a/src/server/editorServices.ts
+++ b/src/server/editorServices.ts
@@ -930,6 +930,7 @@ namespace ts.server {
 
         /*@internal*/
         delayEnsureProjectForOpenFiles() {
+            if (!this.openFiles.size) return;
             this.pendingEnsureProjectForOpenFiles = true;
             this.throttledOperations.schedule(ensureProjectForOpenFileSchedule, /*delay*/ 2500, () => {
                 if (this.pendingProjectUpdates.size !== 0) {
diff --git a/src/testRunner/unittests/tsserver/externalProjects.ts b/src/testRunner/unittests/tsserver/externalProjects.ts
index 57f9aa1544f8d..0e842d7297130 100644
--- a/src/testRunner/unittests/tsserver/externalProjects.ts
+++ b/src/testRunner/unittests/tsserver/externalProjects.ts
@@ -529,7 +529,6 @@ namespace ts.projectSystem {
                     [configFile.path]);
 
                 host.deleteFile(configFile.path);
-                host.checkTimeoutQueueLengthAndRun(1);
 
                 knownProjects = projectService.synchronizeProjectList(map(knownProjects, proj => proj.info!)); // TODO: GH#18217 GH#20039
                 checkNumberOfProjects(projectService, { configuredProjects: 0, externalProjects: 0, inferredProjects: 0 });
diff --git a/src/testRunner/unittests/tsserver/inferredProjects.ts b/src/testRunner/unittests/tsserver/inferredProjects.ts
index 5bb545af0b562..a75a6d0bc6c35 100644
--- a/src/testRunner/unittests/tsserver/inferredProjects.ts
+++ b/src/testRunner/unittests/tsserver/inferredProjects.ts
@@ -450,5 +450,15 @@ namespace ts.projectSystem {
             };
             assert.deepEqual(inferredProject.getTypeAcquisition(), expected, "typeAcquisition should be inferred for inferred projects");
         });
+
+        it("Setting compiler options for inferred projects when there are no open files should not schedule any refresh", () => {
+            const host = createServerHost([commonFile1, libFile]);
+            const projectService = createProjectService(host);
+            projectService.setCompilerOptionsForInferredProjects({
+                allowJs: true,
+                target: ScriptTarget.ES2015
+            });
+            host.checkTimeoutQueueLength(0);
+        });
     });
 }
diff --git a/src/testRunner/unittests/tsserver/projects.ts b/src/testRunner/unittests/tsserver/projects.ts
index 0afe37c463968..f4e56ae71b989 100644
--- a/src/testRunner/unittests/tsserver/projects.ts
+++ b/src/testRunner/unittests/tsserver/projects.ts
@@ -419,7 +419,7 @@ namespace ts.projectSystem {
                 unresolvedImports: response.unresolvedImports,
             });
 
-            host.checkTimeoutQueueLengthAndRun(2);
+            host.checkTimeoutQueueLengthAndRun(1);
             assert.isUndefined(request);
         });
 
diff --git a/src/testRunner/unittests/tsserver/typingsInstaller.ts b/src/testRunner/unittests/tsserver/typingsInstaller.ts
index 26ce8eca6dde4..8a449bccad7cd 100644
--- a/src/testRunner/unittests/tsserver/typingsInstaller.ts
+++ b/src/testRunner/unittests/tsserver/typingsInstaller.ts
@@ -435,7 +435,7 @@ namespace ts.projectSystem {
             installer.installAll(/*expectedCount*/ 1);
 
             checkNumberOfProjects(projectService, { externalProjects: 1 });
-            host.checkTimeoutQueueLengthAndRun(2);
+            host.checkTimeoutQueueLengthAndRun(1);
             checkNumberOfProjects(projectService, { externalProjects: 1 });
             checkProjectActualFiles(p, [file2Jsx.path, file3dts.path, lodashDts.path, reactDts.path]);
         });
@@ -642,7 +642,7 @@ namespace ts.projectSystem {
             installer.installAll(/*expectedCount*/ 1);
 
             checkNumberOfProjects(projectService, { externalProjects: 1 });
-            host.checkTimeoutQueueLengthAndRun(2);
+            host.checkTimeoutQueueLengthAndRun(1);
             checkNumberOfProjects(projectService, { externalProjects: 1 });
             // Commander: Existed as a JS file
             // JQuery: Specified in 'include'
@@ -726,7 +726,7 @@ namespace ts.projectSystem {
             for (const f of typingFiles) {
                 assert.isTrue(host.fileExists(f.path), `expected file ${f.path} to exist`);
             }
-            host.checkTimeoutQueueLengthAndRun(2);
+            host.checkTimeoutQueueLengthAndRun(1);
             checkNumberOfProjects(projectService, { externalProjects: 1 });
             checkProjectActualFiles(p, [file3.path, commander.path, express.path, jquery.path, moment.path, lodash.path]);
         });
@@ -829,7 +829,7 @@ namespace ts.projectSystem {
             assert.equal(installer.pendingRunRequests.length, 0, "expected no throttled requests");
 
             installer.executePendingCommands();
-            host.checkTimeoutQueueLengthAndRun(3); // for 2 projects and 1 refreshing inferred project
+            host.checkTimeoutQueueLengthAndRun(2); // for 2 projects
             checkProjectActualFiles(p1, [file3.path, commander.path, jquery.path, lodash.path, cordova.path]);
             checkProjectActualFiles(p2, [file3.path, grunt.path, gulp.path]);
         });