diff --git a/pkgs/applications/science/logic/why3/with-provers.nix b/pkgs/applications/science/logic/why3/with-provers.nix
index ae0acb1e525c..739064bb6169 100644
--- a/pkgs/applications/science/logic/why3/with-provers.nix
+++ b/pkgs/applications/science/logic/why3/with-provers.nix
@@ -27,6 +27,6 @@ stdenv.mkDerivation {
 
   installPhase = ''
     mkdir -p $out/bin
-    makeWrapper ${why3}/bin/why3 $out/bin/why3 --add-flags "--extra-config $out/share/why3/why3.conf"
+    makeWrapper ${why3}/bin/why3 $out/bin/why3 --add-flags "--config $out/share/why3/why3.conf"
   '';
 }