diff --git a/pkgs/tools/inputmethods/fcitx-engines/fcitx-unikey/default.nix b/pkgs/tools/inputmethods/fcitx-engines/fcitx-unikey/default.nix
index b2cd71d1816e..4581f80a75e0 100644
--- a/pkgs/tools/inputmethods/fcitx-engines/fcitx-unikey/default.nix
+++ b/pkgs/tools/inputmethods/fcitx-engines/fcitx-unikey/default.nix
@@ -11,6 +11,8 @@ stdenv.mkDerivation rec {
 
   buildInputs = [ cmake fcitx gettext pkgconfig ];
 
+  NIX_CFLAGS_COMPILE = "-Wno-narrowing";
+
   preInstall = ''
     substituteInPlace src/cmake_install.cmake \
       --replace ${fcitx} $out
@@ -28,4 +30,4 @@ stdenv.mkDerivation rec {
     maintainers   = with maintainers; [ ericsagnes ];
   };
 
-}
\ No newline at end of file
+}