diff --git a/packages/language-core/index.ts b/packages/language-core/index.ts
index 048a3468..573a14b0 100644
--- a/packages/language-core/index.ts
+++ b/packages/language-core/index.ts
@@ -22,7 +22,7 @@ export const defaultMapperFactory: MapperFactory = mappings => new SourceMap(map
 export function createLanguage<T>(
 	plugins: LanguagePlugin<T>[],
 	scriptRegistry: Map<T, SourceScript<T>>,
-	sync: (id: T, includeFsFiles: boolean) => void
+	sync: (id: T, includeFsFiles: boolean, shouldRegister: boolean) => void
 ) {
 	const virtualCodeToSourceScriptMap = new WeakMap<VirtualCode, SourceScript<T>>();
 	const virtualCodeToSourceMap = new WeakMap<IScriptSnapshot, WeakMap<IScriptSnapshot, Mapper>>();
@@ -34,8 +34,8 @@ export function createLanguage<T>(
 			fromVirtualCode(virtualCode) {
 				return virtualCodeToSourceScriptMap.get(virtualCode)!;
 			},
-			get(id, includeFsFiles = true) {
-				sync(id, includeFsFiles);
+			get(id, includeFsFiles = true, shouldRegister = false) {
+				sync(id, includeFsFiles, shouldRegister);
 				const result = scriptRegistry.get(id);
 				// The sync function provider may not always call the set function due to caching, so it is necessary to explicitly check isAssociationDirty.
 				if (result?.isAssociationDirty) {
@@ -220,7 +220,7 @@ export function createLanguage<T>(
 		sourceScript.isAssociationDirty = false;
 		return {
 			getAssociatedScript(id) {
-				sync(id, true);
+				sync(id, true, true);
 				const relatedSourceScript = scriptRegistry.get(id);
 				if (relatedSourceScript) {
 					relatedSourceScript.targetIds.add(sourceScript.id);
diff --git a/packages/language-core/lib/types.ts b/packages/language-core/lib/types.ts
index b1d77a4d..8f3a3871 100644
--- a/packages/language-core/lib/types.ts
+++ b/packages/language-core/lib/types.ts
@@ -15,7 +15,7 @@ export interface Language<T = unknown> {
 	mapperFactory: MapperFactory;
 	plugins: LanguagePlugin<T>[];
 	scripts: {
-		get(id: T, includeFsFiles?: boolean): SourceScript<T> | undefined;
+		get(id: T, includeFsFiles?: boolean, shouldRegister?: boolean): SourceScript<T> | undefined;
 		set(id: T, snapshot: IScriptSnapshot, languageId?: string, plugins?: LanguagePlugin<T>[]): SourceScript<T> | undefined;
 		delete(id: T): void;
 		fromVirtualCode(virtualCode: VirtualCode): SourceScript<T>;
diff --git a/packages/typescript/lib/node/decorateLanguageServiceHost.ts b/packages/typescript/lib/node/decorateLanguageServiceHost.ts
index ce019de2..88a35c2b 100644
--- a/packages/typescript/lib/node/decorateLanguageServiceHost.ts
+++ b/packages/typescript/lib/node/decorateLanguageServiceHost.ts
@@ -83,7 +83,7 @@ export function decorateLanguageServiceHost(
 	}
 
 	languageServiceHost.getScriptSnapshot = fileName => {
-		const virtualScript = updateVirtualScript(fileName);
+		const virtualScript = updateVirtualScript(fileName, true);
 		if (virtualScript) {
 			return virtualScript.snapshot;
 		}
@@ -92,7 +92,7 @@ export function decorateLanguageServiceHost(
 
 	if (getScriptKind) {
 		languageServiceHost.getScriptKind = fileName => {
-			const virtualScript = updateVirtualScript(fileName);
+			const virtualScript = updateVirtualScript(fileName, false);
 			if (virtualScript) {
 				return virtualScript.scriptKind;
 			}
@@ -100,7 +100,7 @@ export function decorateLanguageServiceHost(
 		};
 	}
 
-	function updateVirtualScript(fileName: string) {
+	function updateVirtualScript(fileName: string, shouldRegister: boolean) {
 		if (crashFileNames.has(fileName)) {
 			return;
 		}
@@ -119,7 +119,7 @@ export function decorateLanguageServiceHost(
 		if (!script || script[0] !== version) {
 			script = [version];
 
-			const sourceScript = language.scripts.get(fileName);
+			const sourceScript = language.scripts.get(fileName, undefined, shouldRegister);
 			if (sourceScript?.generated) {
 				const serviceScript = sourceScript.generated.languagePlugin.typescript?.getServiceScript(sourceScript.generated.root);
 				if (serviceScript) {
diff --git a/packages/typescript/lib/quickstart/createAsyncLanguageServicePlugin.ts b/packages/typescript/lib/quickstart/createAsyncLanguageServicePlugin.ts
index 1585f5f1..90b40998 100644
--- a/packages/typescript/lib/quickstart/createAsyncLanguageServicePlugin.ts
+++ b/packages/typescript/lib/quickstart/createAsyncLanguageServicePlugin.ts
@@ -91,12 +91,19 @@ export function createAsyncLanguageServicePlugin(
 								{ getLanguageId: resolveFileLanguageId },
 							],
 							new FileMap(ts.sys.useCaseSensitiveFileNames),
-							fileName => {
-								let snapshot = getScriptInfo(fileName)?.getSnapshot();
-								if (!snapshot) {
-									// trigger projectService.getOrCreateScriptInfoNotOpenedByClient
-									info.project.getScriptVersion(fileName);
+							(fileName, _, shouldRegister) => {
+								let snapshot: ts.IScriptSnapshot | undefined;
+								if (shouldRegister) {
+									// We need to trigger registration of the script file with the project, see #250
+									snapshot = getScriptSnapshot(fileName);
+								}
+								else {
 									snapshot = getScriptInfo(fileName)?.getSnapshot();
+									if (!snapshot) {
+										// trigger projectService.getOrCreateScriptInfoNotOpenedByClient
+										info.project.getScriptVersion(fileName);
+										snapshot = getScriptInfo(fileName)?.getSnapshot();
+									}
 								}
 								if (snapshot) {
 									language.scripts.set(fileName, snapshot);
diff --git a/packages/typescript/lib/quickstart/createLanguageServicePlugin.ts b/packages/typescript/lib/quickstart/createLanguageServicePlugin.ts
index c33eb699..bf86043b 100644
--- a/packages/typescript/lib/quickstart/createLanguageServicePlugin.ts
+++ b/packages/typescript/lib/quickstart/createLanguageServicePlugin.ts
@@ -34,18 +34,26 @@ export function createLanguageServicePlugin(
 						.map(plugin => plugin.typescript?.extraFileExtensions.map(ext => '.' + ext.extension) ?? [])
 						.flat();
 					projectExternalFileExtensions.set(info.project, extensions);
+					const getScriptSnapshot = info.languageServiceHost.getScriptSnapshot.bind(info.languageServiceHost);
 					const language = createLanguage<string>(
 						[
 							...languagePlugins,
 							{ getLanguageId: resolveFileLanguageId },
 						],
 						new FileMap(ts.sys.useCaseSensitiveFileNames),
-						fileName => {
-							let snapshot = getScriptInfo(fileName)?.getSnapshot();
-							if (!snapshot) {
-								// trigger projectService.getOrCreateScriptInfoNotOpenedByClient
-								info.project.getScriptVersion(fileName);
+						(fileName, _, shouldRegister) => {
+							let snapshot: ts.IScriptSnapshot | undefined;
+							if (shouldRegister) {
+								// We need to trigger registration of the script file with the project, see #250
+								snapshot = getScriptSnapshot(fileName);
+							}
+							else {
 								snapshot = getScriptInfo(fileName)?.getSnapshot();
+								if (!snapshot) {
+									// trigger projectService.getOrCreateScriptInfoNotOpenedByClient
+									info.project.getScriptVersion(fileName);
+									snapshot = getScriptInfo(fileName)?.getSnapshot();
+								}
 							}
 							if (snapshot) {
 								language.scripts.set(fileName, snapshot);