diff --git a/Dockerfile b/Dockerfile
index 078bf6c..65baec4 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -42,7 +42,8 @@ RUN ./emsdk install "${EMSCRIPTEN_VERSION}" && \
 COPY Makefile /root/flang-wasm/Makefile
 RUN . "/opt/emsdk/emsdk_env.sh" && \
     cd "/root/flang-wasm" && \
-    make PREFIX="/opt/flang" && \
+    make PREFIX="/opt/flang" FLANG_WASM_CMAKE_VARS="-DCMAKE_C_COMPILER=clang \
+        -DCMAKE_CXX_COMPILER=clang++ -DLLVM_USE_LINKER=lld" && \
     make PREFIX="/opt/flang" install
 
 # Clean up
diff --git a/Makefile b/Makefile
index 76c51e0..8e5a73f 100644
--- a/Makefile
+++ b/Makefile
@@ -35,12 +35,9 @@ $(FLANG_BIN): $(SOURCE)
 	cmake -G Ninja -S $(SOURCE)/llvm -B $(BUILD) \
 	  -DCMAKE_INSTALL_PREFIX=$(HOST) \
 	  -DCMAKE_BUILD_TYPE=MinSizeRel \
-	  -DCMAKE_C_COMPILER=clang \
-	  -DCMAKE_CXX_COMPILER=clang++ \
 	  -DLLVM_DEFAULT_TARGET_TRIPLE="wasm32-unknown-emscripten" \
 	  -DLLVM_TARGETS_TO_BUILD="WebAssembly" \
 	  -DLLVM_ENABLE_PROJECTS="clang;flang;mlir" \
-	  -DLLVM_USE_LINKER=lld \
 	  $(FLANG_WASM_CMAKE_VARS)
 	TERM=dumb cmake --build $(BUILD)
 	$(MAKE) wasm-runtime
diff --git a/flake.nix b/flake.nix
index 9fafe14..338004b 100644
--- a/flake.nix
+++ b/flake.nix
@@ -62,7 +62,10 @@
             export EM_CACHE=$(pwd)/.emscripten_cache-${pkgs-emscripten.emscripten.version}
             echo emscripten cache dir: $EM_CACHE
 
-            CMAKE_BUILD_PARALLEL_LEVEL=$NIX_BUILD_CORES make SOURCE=${flang-source} PREFIX=$out
+            CMAKE_BUILD_PARALLEL_LEVEL=$NIX_BUILD_CORES make \
+              SOURCE=${flang-source} \
+              PREFIX=$out \
+              FLANG_WASM_CMAKE_VARS="-DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ -DLLVM_USE_LINKER=lld"
           '';
 
           installPhase = ''