diff --git a/docs/generators/typescript-fetch.md b/docs/generators/typescript-fetch.md
index af3dd9162686..40e7ff4eb2cc 100644
--- a/docs/generators/typescript-fetch.md
+++ b/docs/generators/typescript-fetch.md
@@ -76,6 +76,7 @@ sidebar_label: typescript-fetch
 <li>HTTPHeaders</li>
 <li>HTTPMethod</li>
 <li>HTTPQuery</li>
+<li>Index</li>
 <li>JSONApiResponse</li>
 <li>Middleware</li>
 <li>ModelPropertyNaming</li>
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/TypeScriptFetchClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/TypeScriptFetchClientCodegen.java
index b1ab5e4fa818..bb2d108f85d1 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/TypeScriptFetchClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/TypeScriptFetchClientCodegen.java
@@ -312,6 +312,9 @@ private void addExtraReservedWords() {
         this.reservedWords.add("VoidApiResponse");
         this.reservedWords.add("BlobApiResponse");
         this.reservedWords.add("TextApiResponse");
+        // "Index" would create a file "Index.ts" which on case insensitive filesystems
+        // would override our "index.js" file
+        this.reservedWords.add("Index");
     }
 
     private boolean getUseSingleRequestParameter() {