diff --git a/data/meson.build b/data/meson.build
index 1e45638e..c1fbece6 100644
--- a/data/meson.build
+++ b/data/meson.build
@@ -13,8 +13,13 @@ foreach s : sessions
   )
 endforeach
 
+classic_uuids = []
+foreach e : classic_extensions
+    classic_uuids += e + uuid_suffix
+endforeach
+
 mode_conf = configuration_data()
-mode_conf.set('CLASSIC_EXTENSIONS', '"' + '", "'.join(classic_extensions) + '"')
+mode_conf.set('CLASSIC_EXTENSIONS', '"' + '", "'.join(classic_uuids) + '"')
 
 mode_file = 'classic.json'
 configure_file(
diff --git a/extensions/meson.build b/extensions/meson.build
index eba5053c..ed196755 100644
--- a/extensions/meson.build
+++ b/extensions/meson.build
@@ -4,7 +4,7 @@ js_sources = extensionlib
 metadata_name = 'metadata.json'
 
 foreach e : all_extensions
-  uuid = e + '@gnome-shell-extensions.gcampax.github.com'
+  uuid = e + uuid_suffix
 
   metadata_conf = configuration_data()
   metadata_conf.set('extension_id', e)
diff --git a/meson.build b/meson.build
index c7e04181..23a0cfc0 100644
--- a/meson.build
+++ b/meson.build
@@ -32,6 +32,8 @@ else
   shell_version = '.'.join(ver_arr)
 endif
 
+uuid_suffix = '@gnome-shell-extensions.gcampax.github.com'
+
 classic_extensions = [
   'alternate-tab',
   'apps-menu',