diff --git a/AltWidgetExtension.xcconfig b/AltWidgetExtension.xcconfig
index db305864..906558e4 100644
--- a/AltWidgetExtension.xcconfig
+++ b/AltWidgetExtension.xcconfig
@@ -1,3 +1,3 @@
 #include "Build.xcconfig"
 
-PRODUCT_BUNDLE_IDENTIFIER = $(EXTENSION_PREFIX).AltWidget
+PRODUCT_BUNDLE_IDENTIFIER = $(PRODUCT_BUNDLE_IDENTIFIER).AltWidget