diff --git a/pkgs/development/python-modules/generic/default.nix b/pkgs/development/python-modules/generic/default.nix
index 0f5d8499454..4c9c53aab83 100644
--- a/pkgs/development/python-modules/generic/default.nix
+++ b/pkgs/development/python-modules/generic/default.nix
@@ -49,10 +49,9 @@
 
 , ... } @ attrs:
 
-assert (!disabled);
 
 # Keep extra attributes from `attrs`, e.g., `patchPhase', etc.
-python.stdenv.mkDerivation (attrs // {
+if disabled then throw "${name} not supported for interpreter ${python.executable}" else python.stdenv.mkDerivation (attrs // {
   inherit doCheck;
 
   name = namePrefix + name;