diff --git a/build_system/build_sysroot.rs b/build_system/build_sysroot.rs
index 76b602fe7196..d6e231c53b59 100644
--- a/build_system/build_sysroot.rs
+++ b/build_system/build_sysroot.rs
@@ -240,7 +240,7 @@ fn build_clif_sysroot_for_triple(
     rustflags.push_str(&format!(" -Zcodegen-backend={}", cg_clif_dylib_path.to_str().unwrap()));
     // Necessary for MinGW to find rsbegin.o and rsend.o
     rustflags
-        .push_str(&format!(" --sysroot={}", RTSTARTUP_SYSROOT.to_path(dirs).to_str().unwrap()));
+        .push_str(&format!(" --sysroot {}", RTSTARTUP_SYSROOT.to_path(dirs).to_str().unwrap()));
     if channel == "release" {
         rustflags.push_str(" -Zmir-opt-level=3");
     }