diff --git a/.eslintignore b/.eslintignore
deleted file mode 100644
index 08b265ba0..000000000
--- a/.eslintignore
+++ /dev/null
@@ -1,11 +0,0 @@
-dist/**
-.github/**
-docs/Setup.md
-cypress.config.js
-cypress/plugins/index.js
-coverage
-*.json
-node_modules
-
-# autogenereated by langium-cli
-generated/
diff --git a/.eslintignore b/.eslintignore
new file mode 120000
index 000000000..3e4e48b0b
--- /dev/null
+++ b/.eslintignore
@@ -0,0 +1 @@
+.gitignore
\ No newline at end of file
diff --git a/.eslintrc.cjs b/.eslintrc.cjs
index d0bb27bc9..c9428c9f5 100644
--- a/.eslintrc.cjs
+++ b/.eslintrc.cjs
@@ -53,7 +53,7 @@ module.exports = {
     '@typescript-eslint/no-floating-promises': 'error',
     '@typescript-eslint/no-misused-promises': 'error',
     '@typescript-eslint/no-unused-vars': 'warn',
-    '@typescript-eslint/consistent-type-definitions': 'warn',
+    '@typescript-eslint/consistent-type-definitions': 'error',
     '@typescript-eslint/ban-ts-comment': [
       'error',
       {
diff --git a/package.json b/package.json
index 6aa1fec81..858d5ae09 100644
--- a/package.json
+++ b/package.json
@@ -25,8 +25,8 @@
     "dev:vite": "tsx .vite/server.ts",
     "dev:coverage": "pnpm coverage:cypress:clean && VITE_COVERAGE=true pnpm dev:vite",
     "release": "pnpm build",
-    "lint": "cross-env NODE_OPTIONS=--max_old_space_size=8192 eslint --cache --cache-strategy content --ignore-path .gitignore . && pnpm lint:jison && prettier --cache --check .",
-    "lint:fix": "cross-env NODE_OPTIONS=--max_old_space_size=8192 eslint --cache --cache-strategy content --fix --ignore-path .gitignore . && prettier --write . && tsx scripts/fixCSpell.ts",
+    "lint": "cross-env NODE_OPTIONS=--max_old_space_size=8192 eslint --cache --cache-strategy content . && pnpm lint:jison && prettier --cache --check .",
+    "lint:fix": "cross-env NODE_OPTIONS=--max_old_space_size=8192 eslint --cache --cache-strategy content --fix . && prettier --write . && tsx scripts/fixCSpell.ts",
     "lint:jison": "tsx ./scripts/jison/lint.mts",
     "contributors": "tsx scripts/updateContributors.ts",
     "cypress": "cypress run",
diff --git a/packages/mermaid/src/diagrams/class/classTypes.ts b/packages/mermaid/src/diagrams/class/classTypes.ts
index 85be3a4e8..c2f158702 100644
--- a/packages/mermaid/src/diagrams/class/classTypes.ts
+++ b/packages/mermaid/src/diagrams/class/classTypes.ts
@@ -138,7 +138,7 @@ export interface ClassNote {
   text: string;
 }
 
-export type ClassRelation = {
+export interface ClassRelation {
   id1: string;
   id2: string;
   relationTitle1: string;
@@ -152,7 +152,7 @@ export type ClassRelation = {
     type2: number;
     lineType: number;
   };
-};
+}
 
 export interface NamespaceNode {
   id: string;
diff --git a/packages/mermaid/src/diagrams/quadrant-chart/quadrantDb.ts b/packages/mermaid/src/diagrams/quadrant-chart/quadrantDb.ts
index c3a79c911..e65823355 100644
--- a/packages/mermaid/src/diagrams/quadrant-chart/quadrantDb.ts
+++ b/packages/mermaid/src/diagrams/quadrant-chart/quadrantDb.ts
@@ -17,7 +17,10 @@ function textSanitizer(text: string) {
   return sanitizeText(text.trim(), config);
 }
 
-type LexTextObj = { text: string; type: 'text' | 'markdown' };
+interface LexTextObj {
+  text: string;
+  type: 'text' | 'markdown';
+}
 
 const quadrantBuilder = new QuadrantBuilder();
 
diff --git a/packages/parser/src/language/info/module.ts b/packages/parser/src/language/info/module.ts
index 83933aeef..735e16146 100644
--- a/packages/parser/src/language/info/module.ts
+++ b/packages/parser/src/language/info/module.ts
@@ -19,12 +19,12 @@ import { InfoTokenBuilder } from './tokenBuilder.js';
 /**
  * Declaration of `Info` services.
  */
-type InfoAddedServices = {
+interface InfoAddedServices {
   parser: {
     TokenBuilder: InfoTokenBuilder;
     ValueConverter: CommonValueConverter;
   };
-};
+}
 
 /**
  * Union of Langium default services and `Info` services.
diff --git a/packages/parser/src/language/packet/module.ts b/packages/parser/src/language/packet/module.ts
index 40c68916a..7eb65810f 100644
--- a/packages/parser/src/language/packet/module.ts
+++ b/packages/parser/src/language/packet/module.ts
@@ -19,12 +19,12 @@ import { PacketTokenBuilder } from './tokenBuilder.js';
 /**
  * Declaration of `Packet` services.
  */
-type PacketAddedServices = {
+interface PacketAddedServices {
   parser: {
     TokenBuilder: PacketTokenBuilder;
     ValueConverter: CommonValueConverter;
   };
-};
+}
 
 /**
  * Union of Langium default services and `Packet` services.
diff --git a/packages/parser/src/language/pie/module.ts b/packages/parser/src/language/pie/module.ts
index b85daee68..80fc26f86 100644
--- a/packages/parser/src/language/pie/module.ts
+++ b/packages/parser/src/language/pie/module.ts
@@ -19,12 +19,12 @@ import { PieValueConverter } from './valueConverter.js';
 /**
  * Declaration of `Pie` services.
  */
-type PieAddedServices = {
+interface PieAddedServices {
   parser: {
     TokenBuilder: PieTokenBuilder;
     ValueConverter: PieValueConverter;
   };
-};
+}
 
 /**
  * Union of Langium default services and `Pie` services.