diff --git a/src/vs/workbench/api/node/extHostLanguageFeatures.ts b/src/vs/workbench/api/node/extHostLanguageFeatures.ts
index df6512c9b6b..e12de7857c0 100644
--- a/src/vs/workbench/api/node/extHostLanguageFeatures.ts
+++ b/src/vs/workbench/api/node/extHostLanguageFeatures.ts
@@ -282,6 +282,7 @@ export interface CustomCodeAction extends CodeActionDto {
 }
 
 class CodeActionAdapter {
+	private static readonly _maxCodeActionsPerFile: number = 1000;
 
 	constructor(
 		private readonly _documents: ExtHostDocuments,
@@ -302,7 +303,10 @@ class CodeActionAdapter {
 
 		for (const diagnostic of this._diagnostics.getDiagnostics(resource)) {
 			if (ran.intersection(diagnostic.range)) {
-				allDiagnostics.push(diagnostic);
+				const newLen = allDiagnostics.push(diagnostic);
+				if (newLen > CodeActionAdapter._maxCodeActionsPerFile) {
+					break;
+				}
 			}
 		}