diff --git a/compiler+runtime/bin/build-clang b/compiler+runtime/bin/build-clang
index 6a338a0e..8224956e 100755
--- a/compiler+runtime/bin/build-clang
+++ b/compiler+runtime/bin/build-clang
@@ -54,6 +54,7 @@ function build()
   cd "${srcdir}/llvm-build"
 
   cmake -DCMAKE_BUILD_TYPE=Release \
+	-DLLVM_ENABLE_RUNTIMES=all \
         -DCMAKE_CXX_STANDARD=20 \
         -DLLVM_ENABLE_PROJECTS="clang;clang-tools-extra" \
         -DLLVM_TARGETS_TO_BUILD="host" \