diff --git a/src/bootstrap/src/core/builder/cargo.rs b/src/bootstrap/src/core/builder/cargo.rs
index d1d52d82eaa..12dd40d14e9 100644
--- a/src/bootstrap/src/core/builder/cargo.rs
+++ b/src/bootstrap/src/core/builder/cargo.rs
@@ -597,7 +597,7 @@ impl Builder<'_> {
         // sysroot. Passing this cfg enables raw-dylib support instead, which makes the native
         // library unnecessary. This can be removed when windows-rs enables raw-dylib
         // unconditionally.
-        if let Mode::Rustc | Mode::ToolRustc = mode {
+        if let Mode::Rustc | Mode::ToolRustc | Mode::ToolBootstrap = mode {
             rustflags.arg("--cfg=windows_raw_dylib");
         }