diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2668eb75f0f..0ddb4feca9c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1 +1,2 @@
+- Increased extension instance create poll timeout to 1h to match backend (#5969).
 - Refactored `ext:install` to use the latest extension metadata. (#5997)
diff --git a/src/extensions/extensionsApi.ts b/src/extensions/extensionsApi.ts
index bcb50764faf..1ec8b140028 100644
--- a/src/extensions/extensionsApi.ts
+++ b/src/extensions/extensionsApi.ts
@@ -58,7 +58,7 @@ async function createInstanceHelper(
     apiOrigin: extensionsOrigin,
     apiVersion: EXTENSIONS_API_VERSION,
     operationResourceName: createRes.body.name,
-    masterTimeout: 600000,
+    masterTimeout: 3600000,
   });
   return pollRes;
 }