diff --git a/project.inlang.json b/project.inlang.json
index 3d54feeae5..068fb2f092 100644
--- a/project.inlang.json
+++ b/project.inlang.json
@@ -1,8 +1,9 @@
 {
   "$schema": "https://inlang.com/schema/project-settings",
-  "sourceLanguageTag": "en",
+  "sourceLanguageTag": "en-US",
   "languageTags": [
-    "en",
+    "en-US",
+    "en-GB",
     "ar-SA",
     "ca-ES",
     "ckb-KU",
diff --git a/project.inlang/settings.json b/project.inlang/settings.json
index 1341b40643..ed50814d6d 100644
--- a/project.inlang/settings.json
+++ b/project.inlang/settings.json
@@ -1,8 +1,9 @@
 {
   "$schema": "https://inlang.com/schema/project-settings",
-  "sourceLanguageTag": "en",
+  "sourceLanguageTag": "en-US",
   "languageTags": [
-    "en",
+    "en-US",
+    "en-GB",
     "ar-SA",
     "ca-ES",
     "ckb-KU",
@@ -46,4 +47,4 @@
       "@:"
     ]
   }
-}
\ No newline at end of file
+}