diff --git a/pkgs/by-name/sr/srb2kart/package.nix b/pkgs/by-name/sr/srb2kart/package.nix
index 8015e5c39b21..db9a64591472 100644
--- a/pkgs/by-name/sr/srb2kart/package.nix
+++ b/pkgs/by-name/sr/srb2kart/package.nix
@@ -55,6 +55,9 @@ stdenv.mkDerivation (finalAttrs: {
     zlib
   ];
 
+  # Fix build with gcc15 (-std=gnu23)
+  env.NIX_CFLAGS_COMPILE = "-std=gnu17";
+
   cmakeFlags = [
     "-DSRB2_ASSET_DIRECTORY=${finalAttrs.assets}"
     "-DGME_INCLUDE_DIR=${game-music-emu}/include"