diff --git a/pkgs/by-name/ge/geis/package.nix b/pkgs/by-name/ge/geis/package.nix
index 540c84ca8446..4e049ccbc44a 100644
--- a/pkgs/by-name/ge/geis/package.nix
+++ b/pkgs/by-name/ge/geis/package.nix
@@ -73,7 +73,7 @@ stdenv.mkDerivation (finalAttrs: {
   '';
 
   preFixup = ''
-    buildPythonPath "$out $pythonPath"
+    buildPythonPath "$out ''${pythonPath[*]}"
     gappsWrapperArgs+=(--set PYTHONPATH "$program_PYTHONPATH")
   '';