diff --git a/src/bootstrap/builder.rs b/src/bootstrap/builder.rs
index cf7c6596c0238..c6200cfe262a5 100644
--- a/src/bootstrap/builder.rs
+++ b/src/bootstrap/builder.rs
@@ -1915,10 +1915,10 @@ impl<'a> Builder<'a> {
         }
 
         // For `cargo doc` invocations, make rustdoc print the Rust version into the docs
-        // This replaces spaces with newlines because RUSTDOCFLAGS does not
+        // This replaces spaces with tabs because RUSTDOCFLAGS does not
         // support arguments with regular spaces. Hopefully someday Cargo will
         // have space support.
-        let rust_version = self.rust_version().replace(' ', "\n");
+        let rust_version = self.rust_version().replace(' ', "\t");
         rustdocflags.arg("--crate-version").arg(&rust_version);
 
         // Environment variables *required* throughout the build