diff --git a/Steer/src/CollisionContextTool.cxx b/Steer/src/CollisionContextTool.cxx
index 5287e1ef32799..a6c2b0e62e0ca 100644
--- a/Steer/src/CollisionContextTool.cxx
+++ b/Steer/src/CollisionContextTool.cxx
@@ -260,8 +260,15 @@ bool copy_collision_context(const std::string& external_path, int this_tf_id, in
 {
   namespace fs = std::filesystem;
   try {
-    // Construct source file path
-    fs::path filename = fs::path(external_path) / ("collission_context_" + std::to_string(this_tf_id) + ".root");
+    fs::path filename;
+    if (fs::exists(external_path) && fs::is_regular_file(external_path)) {
+      std::cout << "external_path is an existing file: " << external_path << "\n";
+      // use it directly
+      filename = fs::path(external_path);
+    } else {
+      // Construct source file path
+      filename = fs::path(external_path) / ("collission_context_" + std::to_string(this_tf_id) + ".root");
+    }
 
     LOG(info) << "Checking existence of file: " << filename;