diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index d0b4e5c727f..47d6f70d236 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -1834,7 +1834,7 @@ in
 
   kisslicer = callPackage ../tools/misc/kisslicer { };
 
-  klaus = with pythonPackages; toPythonApplication klaus;
+  klaus = with python3Packages; toPythonApplication klaus;
 
   lcdproc = callPackage ../servers/monitoring/lcdproc { };