diff --git a/build.zig b/build.zig
index e0d508b7438a5283afc18265cc7e2d28a6310048..14a46b3f5d7e8bee7bfbfcc4d1c57e7d18c35676 100644
--- a/build.zig
+++ b/build.zig
@@ -769,6 +769,7 @@ const zig_cpp_sources = [_][]const u8{
     // These are planned to stay even when we are self-hosted.
     "src/zig_llvm.cpp",
     "src/zig_clang.cpp",
+    "src/zig_llvm-ar.cpp",
     "src/zig_clang_driver.cpp",
     "src/zig_clang_cc1_main.cpp",
     "src/zig_clang_cc1as_main.cpp",