diff --git a/pkgs/by-name/sd/SDL2_gfx/package.nix b/pkgs/by-name/sd/SDL2_gfx/package.nix
index 4d6f6d77bbd7..5ae903baf1c2 100644
--- a/pkgs/by-name/sd/SDL2_gfx/package.nix
+++ b/pkgs/by-name/sd/SDL2_gfx/package.nix
@@ -38,6 +38,10 @@ stdenv.mkDerivation (finalAttrs: {
     "dev"
   ];
 
+  # Missing 'sincos()' implementation fails linking projects
+  # like 'freeciv_sdl2'.
+  env.NIX_LDFLAGS = "-lm";
+
   configureFlags = [
     (lib.enableFeature enableMmx "mmx")
     (lib.enableFeature enableSdltest "sdltest")