diff --git a/pkgs/top-level/python-packages.nix b/pkgs/top-level/python-packages.nix
index 2859f2283b9e..ba25debd5519 100644
--- a/pkgs/top-level/python-packages.nix
+++ b/pkgs/top-level/python-packages.nix
@@ -614,6 +614,12 @@ in {
   pyqt5 = pkgs.libsForQt5.callPackage ../development/python-modules/pyqt/5.x.nix {
     pythonPackages = self;
   };
+
+  /*
+    `pyqt5_with_qtwebkit` should not be used by python libraries in
+    pkgs/development/python-modules/*. Putting this attribute in
+    `propagatedBuildInputs` may cause collisions.
+  */
   pyqt5_with_qtwebkit = self.pyqt5.override { withWebKit = true; };
 
   pysc2 = callPackage ../development/python-modules/pysc2 { };