diff --git a/pkgs/by-name/li/libsquish/package.nix b/pkgs/by-name/li/libsquish/package.nix
index e62af249fa52..adb805525272 100644
--- a/pkgs/by-name/li/libsquish/package.nix
+++ b/pkgs/by-name/li/libsquish/package.nix
@@ -30,7 +30,8 @@ stdenv.mkDerivation (finalAttrs: {
   cmakeFlags = [
     (lib.cmakeBool "BUILD_SHARED_LIBS" true)
     (lib.cmakeFeature "CMAKE_POLICY_VERSION_MINIMUM" "3.5")
-  ];
+  ]
+  ++ lib.optional (!stdenv.hostPlatform.isx86) (lib.cmakeBool "BUILD_SQUISH_WITH_SSE2" false);
 
   meta = {
     description = "Library for compressing images with the DXT/S3TC standard";
diff --git a/pkgs/by-name/vc/vcmi/package.nix b/pkgs/by-name/vc/vcmi/package.nix
index a805655ac767..521c34ddb7cd 100644
--- a/pkgs/by-name/vc/vcmi/package.nix
+++ b/pkgs/by-name/vc/vcmi/package.nix
@@ -66,6 +66,9 @@ stdenv.mkDerivation (finalAttrs: {
   ]
   ++ lib.optional enableMMAI onnxruntime;
 
+  # GCC 15 ICE in -Wmismatched-tags diagnostic during template specialisation lookup
+  env.NIX_CFLAGS_COMPILE = lib.optionalString stdenv.cc.isGNU "-Wno-mismatched-tags";
+
   cmakeFlags = [
     (lib.cmakeBool "ENABLE_CLIENT" true)
     (lib.cmakeBool "ENABLE_LUA" true)