diff --git a/fava.nix b/fava.nix
index f9958ef..8801fa1 100644
--- a/fava.nix
+++ b/fava.nix
@@ -10,6 +10,7 @@ let
   # dependencies, avoiding duplicate package conflicts in the closure.
   stripFavaDep = ext: ext.overridePythonAttrs (old: {
     dependencies = builtins.filter (dep: (dep.pname or "") != "fava") (old.dependencies or []);
+    pythonRuntimeDepsCheck = false;
   });
 
   favaWithExtensions = if cfg.extensions == [] then cfg.package else