diff --git a/pkgs/tools/inputmethods/ibus/wrapper.nix b/pkgs/tools/inputmethods/ibus/wrapper.nix
index 690043791b20..74333c459e8f 100644
--- a/pkgs/tools/inputmethods/ibus/wrapper.nix
+++ b/pkgs/tools/inputmethods/ibus/wrapper.nix
@@ -23,7 +23,7 @@ let
 
     for prog in ibus ibus-daemon ibus-setup; do
         wrapProgram "$out/bin/$prog" \
-          --prefix GDK_PIXBUF_MODULE_FILE : ${librsvg.out}/lib/gdk-pixbuf-2.0/2.10.0/loaders.cache \
+          --set GDK_PIXBUF_MODULE_FILE ${librsvg.out}/lib/gdk-pixbuf-2.0/2.10.0/loaders.cache \
           --prefix GI_TYPELIB_PATH : "$GI_TYPELIB_PATH:$out/lib/girepository-1.0" \
           --prefix GIO_EXTRA_MODULES : "${dconf}/lib/gio/modules" \
           --set IBUS_COMPONENT_PATH "$out/share/ibus/component/" \