diff --git a/src/bootstrap/lib.rs b/src/bootstrap/lib.rs
index 6a51450a777e8..0a7aff62257a5 100644
--- a/src/bootstrap/lib.rs
+++ b/src/bootstrap/lib.rs
@@ -599,6 +599,9 @@ impl Build {
 
             let mut git = self.config.git();
             if let Some(branch) = current_branch {
+                // If there is a tag named after the current branch, git will try to disambiguate by prepending `heads/` to the branch name.
+                // This syntax isn't accepted by `branch.{branch}`. Strip it.
+                let branch = branch.strip_prefix("heads/").unwrap_or(&branch);
                 git.arg("-c").arg(format!("branch.{branch}.remote=origin"));
             }
             git.args(&["submodule", "update", "--init", "--recursive", "--depth=1"]);