diff --git a/pkgs/applications/networking/irc/weechat/scripts/default.nix b/pkgs/applications/networking/irc/weechat/scripts/default.nix
index 439e0e11614..cd9ecbf4337 100644
--- a/pkgs/applications/networking/irc/weechat/scripts/default.nix
+++ b/pkgs/applications/networking/irc/weechat/scripts/default.nix
@@ -6,7 +6,7 @@
   };
 
   weechat-matrix-bridge = callPackage ./weechat-matrix-bridge {
-    inherit (luaPackages) cjson;
+    inherit (luaPackages) cjson luaffi;
   };
 
   wee-slack = callPackage ./wee-slack {
diff --git a/pkgs/applications/networking/irc/weechat/scripts/weechat-matrix-bridge/default.nix b/pkgs/applications/networking/irc/weechat/scripts/weechat-matrix-bridge/default.nix
index 233fe418df3..ea5052f37a3 100644
--- a/pkgs/applications/networking/irc/weechat/scripts/weechat-matrix-bridge/default.nix
+++ b/pkgs/applications/networking/irc/weechat/scripts/weechat-matrix-bridge/default.nix
@@ -31,9 +31,9 @@ stdenv.mkDerivation {
     mkdir -p $out/{share,lib}
 
     cp {matrix.lua,olm.lua} $out/share
-    cp ${cjson}/lib/lua/5.2/cjson.so $out/lib/cjson.so
+    cp ${cjson}/lib/lua/${cjson.lua.luaversion}/cjson.so $out/lib/cjson.so
     cp ${olm}/lib/libolm.so $out/lib/libolm.so
-    cp ${luaffi}/lib/ffi.so $out/lib/ffi.so
+    cp ${luaffi}/lib/lua/${luaffi.lua.luaversion}/ffi.so $out/lib/ffi.so
   '';
 
   meta = with stdenv.lib; {