diff --git a/src/bootstrap/src/core/build_steps/run.rs b/src/bootstrap/src/core/build_steps/run.rs
index 9f7248b80f763..b9a4c1bf9b44b 100644
--- a/src/bootstrap/src/core/build_steps/run.rs
+++ b/src/bootstrap/src/core/build_steps/run.rs
@@ -6,6 +6,7 @@
 use std::path::PathBuf;
 
 use build_helper::exit;
+use build_helper::git::get_git_untracked_files;
 use clap_complete::{Generator, shells};
 
 use crate::core::build_steps::dist::distdir;
@@ -208,6 +209,16 @@ impl Step for CollectLicenseMetadata {
 
         let dest = builder.src.join("license-metadata.json");
 
+        if !builder.config.dry_run() {
+            builder.require_and_update_all_submodules();
+            if let Ok(Some(untracked)) = get_git_untracked_files(None) {
+                eprintln!(
+                    "Warning: {} untracked files may cause the license report to be incorrect.",
+                    untracked.len()
+                );
+            }
+        }
+
         let mut cmd = builder.tool_cmd(Tool::CollectLicenseMetadata);
         cmd.env("REUSE_EXE", reuse);
         cmd.env("DEST", &dest);