diff --git a/package-lock.json b/package-lock.json
index c19fc25c..265a4950 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -15850,7 +15850,7 @@
     },
     "packages/helix-shared-body-data": {
       "name": "@adobe/helix-shared-body-data",
-      "version": "2.1.1",
+      "version": "2.1.2",
       "license": "Apache-2.0",
       "dependencies": {
         "@adobe/fetch": "^4.0.1",
@@ -15891,7 +15891,7 @@
     },
     "packages/helix-shared-config": {
       "name": "@adobe/helix-shared-config",
-      "version": "10.4.5",
+      "version": "10.4.6",
       "license": "Apache-2.0",
       "dependencies": {
         "@adobe/fetch": "^4.0.1",
@@ -15948,7 +15948,7 @@
     },
     "packages/helix-shared-git": {
       "name": "@adobe/helix-shared-git",
-      "version": "3.0.9",
+      "version": "3.0.10",
       "license": "Apache-2.0",
       "dependencies": {
         "@adobe/helix-shared-prune": "^1.0.5",
@@ -16257,10 +16257,10 @@
     },
     "packages/helix-shared-secrets": {
       "name": "@adobe/helix-shared-secrets",
-      "version": "2.2.6",
+      "version": "2.2.7",
       "license": "Apache-2.0",
       "dependencies": {
-        "@adobe/fetch": "^4.0.1",
+        "@adobe/fetch": "^4.1.3",
         "@adobe/helix-shared-wrap": "^1.0.5",
         "aws4": "^1.12.0"
       },
diff --git a/packages/helix-shared-config/src/schemas/sitemap-language.schema.json b/packages/helix-shared-config/src/schemas/sitemap-language.schema.json
index 60649669..4eb09554 100644
--- a/packages/helix-shared-config/src/schemas/sitemap-language.schema.json
+++ b/packages/helix-shared-config/src/schemas/sitemap-language.schema.json
@@ -55,6 +55,14 @@
         "/en/{path}",
         "/german/{path}"
       ]
+    },
+    "extension": {
+      "type": "string",
+      "title": "Location extension",
+      "description": "Extension to append to every location generated for this sitemap. Default is empty",
+      "examples": [
+        ".html"
+      ]
     }
   },
   "required": [
diff --git a/packages/helix-shared-config/src/schemas/sitemap.schema.json b/packages/helix-shared-config/src/schemas/sitemap.schema.json
index 79c0df49..d787bdcb 100644
--- a/packages/helix-shared-config/src/schemas/sitemap.schema.json
+++ b/packages/helix-shared-config/src/schemas/sitemap.schema.json
@@ -46,6 +46,14 @@
       "additionalProperties": {
         "$ref": "https://ns.adobe.com/helix/shared/sitemap-language"
       }
+    },
+    "extension": {
+      "type": "string",
+      "title": "Location extension",
+      "description": "Extension to append to every location generated for this sitemap. Default is empty",
+      "examples": [
+        ".html"
+      ]
     }
   },
   "required": []
diff --git a/packages/helix-shared-config/test/sitemapconfigs.test.js b/packages/helix-shared-config/test/sitemapconfigs.test.js
index af6d276c..3dc1c5fc 100644
--- a/packages/helix-shared-config/test/sitemapconfigs.test.js
+++ b/packages/helix-shared-config/test/sitemapconfigs.test.js
@@ -27,6 +27,11 @@ const tests = [
     config: 'simple.yaml',
     result: 'simple.json',
   },
+  {
+    title: 'loads a simple example with extension',
+    config: 'simple-extension.yaml',
+    result: 'simple-extension.json',
+  },
   {
     title: 'loads an example with multiple languages',
     config: 'multilang.yaml',
diff --git a/packages/helix-shared-config/test/specs/sitemapconfigs/multilang-extension.json b/packages/helix-shared-config/test/specs/sitemapconfigs/multilang-extension.json
new file mode 100644
index 00000000..e373d1b5
--- /dev/null
+++ b/packages/helix-shared-config/test/specs/sitemapconfigs/multilang-extension.json
@@ -0,0 +1,28 @@
+{
+  "sitemaps": {
+    "multilang": {
+      "origin": "https://www.example.com",
+      "languages": {
+        "en": {
+          "source": "/en/query-index.json",
+          "destination": "/sitemap-en.xml",
+          "hreflang": "en"
+        },
+        "fr": {
+          "source": "/fr/query-index.json",
+          "destination": "/sitemap-fr.xml",
+          "hreflang": "fr",
+          "alternate": "/fr/{path}",
+          "extension": ".html"
+        },
+        "la": {
+          "source": "/la/query-index.json",
+          "destination": "/sitemap-la.xml",
+          "hreflang": ["es-VE","es-SV","es-PA"],
+          "alternate": "/la/{path}"
+        }
+      }
+    }
+  },
+  "version": 1
+}
diff --git a/packages/helix-shared-config/test/specs/sitemapconfigs/multilang-extension.yaml b/packages/helix-shared-config/test/specs/sitemapconfigs/multilang-extension.yaml
new file mode 100644
index 00000000..ff58f186
--- /dev/null
+++ b/packages/helix-shared-config/test/specs/sitemapconfigs/multilang-extension.yaml
@@ -0,0 +1,24 @@
+version: 1
+
+sitemaps:
+  multilang:
+    origin: https://www.example.com
+    languages:
+      en:
+        source: /en/query-index.json
+        destination: /sitemap-en.xml
+        hreflang: en
+      fr:
+        source: /fr/query-index.json
+        destination: /sitemap-fr.xml
+        hreflang: fr
+        alternate: /fr/{path}
+        extension: .html
+      la:
+        source: /la/query-index.json
+        destination: /sitemap-la.xml
+        hreflang:
+          - es-VE
+          - es-SV
+          - es-PA
+        alternate: /la/{path}
diff --git a/packages/helix-shared-config/test/specs/sitemapconfigs/simple-extension.json b/packages/helix-shared-config/test/specs/sitemapconfigs/simple-extension.json
new file mode 100644
index 00000000..652cf533
--- /dev/null
+++ b/packages/helix-shared-config/test/specs/sitemapconfigs/simple-extension.json
@@ -0,0 +1,11 @@
+{
+  "sitemaps": {
+    "simple": {
+      "origin": "https://www.example.com",
+      "source": "/query-index.json",
+      "destination": "/sitemap-en.xml",
+      "extension": ".html"
+    }
+  },
+  "version": 1
+}
diff --git a/packages/helix-shared-config/test/specs/sitemapconfigs/simple-extension.yaml b/packages/helix-shared-config/test/specs/sitemapconfigs/simple-extension.yaml
new file mode 100644
index 00000000..7a3952b6
--- /dev/null
+++ b/packages/helix-shared-config/test/specs/sitemapconfigs/simple-extension.yaml
@@ -0,0 +1,8 @@
+version: 1
+
+sitemaps:
+  simple:
+    origin: https://www.example.com
+    source: /query-index.json
+    destination: /sitemap-en.xml
+    extension: .html