diff --git a/pkgs/tools/backup/duplicity/default.nix b/pkgs/tools/backup/duplicity/default.nix
index 42db541cf3b..24e1a2954ed 100644
--- a/pkgs/tools/backup/duplicity/default.nix
+++ b/pkgs/tools/backup/duplicity/default.nix
@@ -48,7 +48,7 @@ pythonPackages.buildPythonApplication rec {
     librsync
   ];
 
-  propagatedBuildInputs = with pythonPackages; [
+  pythonPath = with pythonPackages; [
     b2sdk
     boto
     boto3