diff --git a/vcs2l/clients/git.py b/vcs2l/clients/git.py
index 4f013a8..278ad43 100644
--- a/vcs2l/clients/git.py
+++ b/vcs2l/clients/git.py
@@ -25,7 +25,10 @@ def get_git_version(cls):
 
     @staticmethod
     def is_repository(path):
-        return os.path.isdir(os.path.join(path, '.git'))
+        """Check if the given path is a git repository or a submodule."""
+        return os.path.isdir(os.path.join(path, '.git')) or os.path.isfile(
+            os.path.join(path, '.git')
+        )
 
     def __init__(self, path):
         super(GitClient, self).__init__(path)