diff --git a/pkgs/development/compilers/llvm/common/clang/default.nix b/pkgs/development/compilers/llvm/common/clang/default.nix
index 5c9662c24d58..45b8090d8214 100644
--- a/pkgs/development/compilers/llvm/common/clang/default.nix
+++ b/pkgs/development/compilers/llvm/common/clang/default.nix
@@ -72,9 +72,7 @@ let
       # `clang-pseudo-gen`: https://github.com/llvm/llvm-project/commit/cd2292ef824591cc34cc299910a3098545c840c7
       "-DCLANG_TIDY_CONFUSABLE_CHARS_GEN=${buildLlvmTools.libclang.dev}/bin/clang-tidy-confusable-chars-gen"
       "-DCLANG_PSEUDO_GEN=${buildLlvmTools.libclang.dev}/bin/clang-pseudo-gen"
-    ]) ++ lib.optionals (stdenv.targetPlatform.useLLVM or false) [
-      "-DCLANG_DEFAULT_CXX_STDLIB=ON"
-    ] ++ lib.optional (lib.versionAtLeast release_version "20") "-DLLVM_DIR=${libllvm.dev}/lib/cmake/llvm"
+    ]) ++ lib.optional (lib.versionAtLeast release_version "20") "-DLLVM_DIR=${libllvm.dev}/lib/cmake/llvm"
       ++ devExtraCmakeFlags;
 
     postPatch = ''