diff --git a/src/server/editorServices.ts b/src/server/editorServices.ts
index 47d0dc71f2faa..f98f0dce2dbd0 100644
--- a/src/server/editorServices.ts
+++ b/src/server/editorServices.ts
@@ -1743,7 +1743,9 @@ namespace ts.server {
 
             return project?.isSolution() ?
                 project.getDefaultChildProjectFromSolution(info) :
-                project;
+                project && projectContainsInfoDirectly(project, info) ?
+                    project :
+                    undefined;
         }
 
         /**
diff --git a/src/testRunner/unittests/tsbuild/watchMode.ts b/src/testRunner/unittests/tsbuild/watchMode.ts
index 308c229776dc4..69faba35c318e 100644
--- a/src/testRunner/unittests/tsbuild/watchMode.ts
+++ b/src/testRunner/unittests/tsbuild/watchMode.ts
@@ -15,6 +15,13 @@ namespace ts.tscWatch {
         return ts.createSolutionBuilder(host, rootNames, defaultOptions || {});
     }
 
+    export function ensureErrorFreeBuild(host: WatchedSystem, rootNames: readonly string[]) {
+        // ts build should succeed
+        const solutionBuilder = createSolutionBuilder(host, rootNames, {});
+        solutionBuilder.build();
+        assert.equal(host.getOutput().length, 0, JSON.stringify(host.getOutput(), /*replacer*/ undefined, " "));
+    }
+
     type OutputFileStamp = [string, Date | undefined, boolean];
     function transformOutputToOutputFileStamp(f: string, host: TsBuildWatchSystem): OutputFileStamp {
         return [f, host.getModifiedTime(f), host.writtenFiles.has(host.toFullPath(f))] as OutputFileStamp;
diff --git a/src/testRunner/unittests/tsserver/configuredProjects.ts b/src/testRunner/unittests/tsserver/configuredProjects.ts
index 4c61106a1d67e..b8ec47946a302 100644
--- a/src/testRunner/unittests/tsserver/configuredProjects.ts
+++ b/src/testRunner/unittests/tsserver/configuredProjects.ts
@@ -1050,6 +1050,64 @@ declare var console: {
                 });
             });
         });
+
+        it("when default configured project does not contain the file", () => {
+            const barConfig: File = {
+                path: `${tscWatch.projectRoot}/bar/tsconfig.json`,
+                content: "{}"
+            };
+            const barIndex: File = {
+                path: `${tscWatch.projectRoot}/bar/index.ts`,
+                content: `import {foo} from "../foo/lib";
+foo();`
+            };
+            const fooBarConfig: File = {
+                path: `${tscWatch.projectRoot}/foobar/tsconfig.json`,
+                content: barConfig.path
+            };
+            const fooBarIndex: File = {
+                path: `${tscWatch.projectRoot}/foobar/index.ts`,
+                content: barIndex.content
+            };
+            const fooConfig: File = {
+                path: `${tscWatch.projectRoot}/foo/tsconfig.json`,
+                content: JSON.stringify({
+                    include: ["index.ts"],
+                    compilerOptions: {
+                        declaration: true,
+                        outDir: "lib"
+                    }
+                })
+            };
+            const fooIndex: File = {
+                path: `${tscWatch.projectRoot}/foo/index.ts`,
+                content: `export function foo() {}`
+            };
+            const host = createServerHost([barConfig, barIndex, fooBarConfig, fooBarIndex, fooConfig, fooIndex, libFile]);
+            tscWatch.ensureErrorFreeBuild(host, [fooConfig.path]);
+            const fooDts = `${tscWatch.projectRoot}/foo/lib/index.d.ts`;
+            assert.isTrue(host.fileExists(fooDts));
+            const session = createSession(host);
+            const service = session.getProjectService();
+            service.openClientFile(barIndex.path);
+            checkProjectActualFiles(service.configuredProjects.get(barConfig.path)!, [barIndex.path, fooDts, libFile.path, barConfig.path]);
+            service.openClientFile(fooBarIndex.path);
+            checkProjectActualFiles(service.configuredProjects.get(fooBarConfig.path)!, [fooBarIndex.path, fooDts, libFile.path, fooBarConfig.path]);
+            service.openClientFile(fooIndex.path);
+            checkProjectActualFiles(service.configuredProjects.get(fooConfig.path)!, [fooIndex.path, libFile.path, fooConfig.path]);
+            service.openClientFile(fooDts);
+            session.executeCommandSeq<protocol.GetApplicableRefactorsRequest>({
+                command: protocol.CommandTypes.GetApplicableRefactors,
+                arguments: {
+                    file: fooDts,
+                    startLine: 1,
+                    startOffset: 1,
+                    endLine: 1,
+                    endOffset: 1
+                }
+            });
+            assert.equal(service.tryGetDefaultProjectForFile(server.toNormalizedPath(fooDts)), service.configuredProjects.get(barConfig.path));
+        });
     });
 
     describe("unittests:: tsserver:: ConfiguredProjects:: non-existing directories listed in config file input array", () => {
diff --git a/src/testRunner/unittests/tsserver/projectReferenceCompileOnSave.ts b/src/testRunner/unittests/tsserver/projectReferenceCompileOnSave.ts
index e8442e07e69cd..e4301b3c271f7 100644
--- a/src/testRunner/unittests/tsserver/projectReferenceCompileOnSave.ts
+++ b/src/testRunner/unittests/tsserver/projectReferenceCompileOnSave.ts
@@ -469,9 +469,7 @@ ${appendDts}`
             const host = createServerHost([libFile, tsbaseJson, buttonConfig, buttonSource, siblingConfig, siblingSource], { useCaseSensitiveFileNames: true });
 
             // ts build should succeed
-            const solutionBuilder = tscWatch.createSolutionBuilder(host, [siblingConfig.path], {});
-            solutionBuilder.build();
-            assert.equal(host.getOutput().length, 0, JSON.stringify(host.getOutput(), /*replacer*/ undefined, " "));
+            tscWatch.ensureErrorFreeBuild(host, [siblingConfig.path]);
             const sourceJs = changeExtension(siblingSource.path, ".js");
             const expectedSiblingJs = host.readFile(sourceJs);
 
diff --git a/src/testRunner/unittests/tsserver/projectReferences.ts b/src/testRunner/unittests/tsserver/projectReferences.ts
index 2eb7d7710cefb..8da081d82c1bf 100644
--- a/src/testRunner/unittests/tsserver/projectReferences.ts
+++ b/src/testRunner/unittests/tsserver/projectReferences.ts
@@ -2,12 +2,8 @@ namespace ts.projectSystem {
     describe("unittests:: tsserver:: with project references and tsbuild", () => {
         function createHost(files: readonly TestFSWithWatch.FileOrFolderOrSymLink[], rootNames: readonly string[]) {
             const host = createServerHost(files);
-
             // ts build should succeed
-            const solutionBuilder = tscWatch.createSolutionBuilder(host, rootNames, {});
-            solutionBuilder.build();
-            assert.equal(host.getOutput().length, 0, JSON.stringify(host.getOutput(), /*replacer*/ undefined, " "));
-
+            tscWatch.ensureErrorFreeBuild(host, rootNames);
             return host;
         }