diff --git a/extensions/crossmodel-lang/src/language-server/lexer/cross-model-indentation-tokens.ts b/extensions/crossmodel-lang/src/language-server/lexer/cross-model-indentation-tokens.ts
index 746bc44f..ee611cb3 100644
--- a/extensions/crossmodel-lang/src/language-server/lexer/cross-model-indentation-tokens.ts
+++ b/extensions/crossmodel-lang/src/language-server/lexer/cross-model-indentation-tokens.ts
@@ -73,7 +73,7 @@ function matchIndentBase(text: string, offset: number, matchedTokens: IToken[],
 
     // indentation can only be matched at the start of a line.
     if (isFirstLine || isStartOfLine) {
-        let currIndentLevel: number | undefined = undefined;
+        let currIndentLevel: number | undefined;
         const prevIndentLevel = indentStack.getLast();
 
         const wsRegExp = /[ ]+/y;
diff --git a/extensions/crossmodel-lang/src/language-server/lexer/cross-model-token-generator.ts b/extensions/crossmodel-lang/src/language-server/lexer/cross-model-token-generator.ts
index 5e68e8c8..183a14b7 100644
--- a/extensions/crossmodel-lang/src/language-server/lexer/cross-model-token-generator.ts
+++ b/extensions/crossmodel-lang/src/language-server/lexer/cross-model-token-generator.ts
@@ -27,10 +27,10 @@ export class CrossModelTokenBuilder extends DefaultTokenBuilder {
         const tokens: TokenType[] = super.buildTokens(grammar, options) as TokenType[];
 
         const updatedTokens: TokenType[] = [];
-        let tokenWithSpaces: TokenType | undefined = undefined;
-        let tokenIndent: TokenType | undefined = undefined;
-        let tokenDedent: TokenType | undefined = undefined;
-        let tokenNewLine: TokenType | undefined = undefined;
+        let tokenWithSpaces: TokenType | undefined;
+        let tokenIndent: TokenType | undefined;
+        let tokenDedent: TokenType | undefined;
+        let tokenNewLine: TokenType | undefined;
 
         for (const token of tokens) {
             if (token.name === NAMES.SPACES) {
diff --git a/extensions/crossmodel-lang/src/model-server/model-server.ts b/extensions/crossmodel-lang/src/model-server/model-server.ts
index a505c754..27e451e3 100644
--- a/extensions/crossmodel-lang/src/model-server/model-server.ts
+++ b/extensions/crossmodel-lang/src/model-server/model-server.ts
@@ -57,7 +57,7 @@ export class ModelServer implements Disposable {
      */
     async requestModelDiagramNode(uri: string, id: string): Promise<DiagramNodeEntity | undefined> {
         const root = (await this.modelService.request(uri)) as CrossModelRootAst;
-        let diagramNode: DiagramNode | undefined = undefined;
+        let diagramNode: DiagramNode | undefined;
 
         if (!root || !root.diagram) {
             throw new Error('Something went wrong loading the diagram');
diff --git a/packages/form-client/src/browser/form-editor-widget.tsx b/packages/form-client/src/browser/form-editor-widget.tsx
index 7d7e8cc1..9e726a93 100644
--- a/packages/form-client/src/browser/form-editor-widget.tsx
+++ b/packages/form-client/src/browser/form-editor-widget.tsx
@@ -41,8 +41,8 @@ export class FormEditorWidget extends ReactWidget implements NavigatableWidget,
     @inject(CommandService) protected commandService: CommandService;
     @inject(ModelServiceClient) protected formClient: ModelServiceClient;
 
-    protected syncedModel: CrossModelRoot | undefined = undefined;
-    protected error: string | undefined = undefined;
+    protected syncedModel: CrossModelRoot | undefined;
+    protected error: string | undefined;
 
     @postConstruct()
     init(): void {
diff --git a/packages/property-view/src/browser/model-property-widget.tsx b/packages/property-view/src/browser/model-property-widget.tsx
index 3e221099..51c1a52b 100644
--- a/packages/property-view/src/browser/model-property-widget.tsx
+++ b/packages/property-view/src/browser/model-property-widget.tsx
@@ -24,7 +24,7 @@ export class ModelPropertyWidget extends ReactWidget implements PropertyViewCont
     @inject(ModelService) protected modelService: ModelService;
     @inject(ApplicationShell) protected shell: ApplicationShell;
 
-    protected model: CrossModelRoot | undefined = undefined;
+    protected model: CrossModelRoot | undefined;
     protected uri: string;
 
     constructor() {