diff --git a/manifests/ppa.pp b/manifests/ppa.pp
index 210fdb5fb3..61d9d8f19c 100644
--- a/manifests/ppa.pp
+++ b/manifests/ppa.pp
@@ -56,7 +56,7 @@
   $sources_list_d_filename = if versioncmp($facts['os']['release']['full'], '23.10') < 0 {
     "${dash_filename_no_specialchars}-${release}.list"
   } else {
-    $"${dash_filename_no_specialchars}-${release}.sources"
+    "${dash_filename_no_specialchars}-${release}.sources"
   }
 
   if versioncmp($facts['os']['release']['full'], '21.04') < 0 {