diff --git a/.eslintrc.cjs b/.eslintrc.cjs
index 49e1aaaa66..9b3426ce8f 100644
--- a/.eslintrc.cjs
+++ b/.eslintrc.cjs
@@ -63,6 +63,17 @@ module.exports = {
         minimumDescriptionLength: 10,
       },
     ],
+    '@typescript-eslint/naming-convention': [
+      'error',
+      {
+        selector: 'typeLike',
+        format: ['PascalCase'],
+        custom: {
+          regex: '^I[A-Z]',
+          match: false,
+        },
+      },
+    ],
     'json/*': ['error', 'allowComments'],
     '@cspell/spellchecker': [
       'error',
diff --git a/packages/mermaid/src/diagrams/quadrant-chart/quadrantBuilder.ts b/packages/mermaid/src/diagrams/quadrant-chart/quadrantBuilder.ts
index 380a79f190..9f5e3933a1 100644
--- a/packages/mermaid/src/diagrams/quadrant-chart/quadrantBuilder.ts
+++ b/packages/mermaid/src/diagrams/quadrant-chart/quadrantBuilder.ts
@@ -53,7 +53,7 @@ export interface QuadrantBuildType {
   borderLines?: QuadrantLineType[];
 }
 
-export interface quadrantBuilderData {
+export interface QuadrantBuilderData {
   titleText: string;
   quadrant1Text: string;
   quadrant2Text: string;
@@ -116,7 +116,7 @@ interface CalculateSpaceData {
 export class QuadrantBuilder {
   private config: QuadrantBuilderConfig;
   private themeConfig: QuadrantBuilderThemeConfig;
-  private data: quadrantBuilderData;
+  private data: QuadrantBuilderData;
 
   constructor() {
     this.config = this.getDefaultConfig();
@@ -124,7 +124,7 @@ export class QuadrantBuilder {
     this.data = this.getDefaultData();
   }
 
-  getDefaultData(): quadrantBuilderData {
+  getDefaultData(): QuadrantBuilderData {
     return {
       titleText: '',
       quadrant1Text: '',
@@ -194,7 +194,7 @@ export class QuadrantBuilder {
     log.info('clear called');
   }
 
-  setData(data: Partial<quadrantBuilderData>) {
+  setData(data: Partial<QuadrantBuilderData>) {
     this.data = { ...this.data, ...data };
   }