diff --git a/libwyag.py b/libwyag.py
index 4e3c7bf..ef6433f 100644
--- a/libwyag.py
+++ b/libwyag.py
@@ -1487,6 +1487,7 @@ def tree_from_index(repo, index, commit_map, author, commit_time, message):
         if path in commit_map:
             (subcommit_hash, subcommit) = commit_map[path]
         else:
+            subcommit_hash = None
             subcommit = None
 
         if subcommit == None or subcommit.kvlm[b'tree'] != sha.encode('ascii'):
@@ -1530,12 +1531,18 @@ def cmd_commit(args):
     repo = repo_find()
     index = index_read(repo)
     root_commit_sha = object_find(repo, "HEAD")
-    root_commit = object_read(repo, root_commit_sha)
+    if root_commit_sha:
+        root_commit = object_read(repo, root_commit_sha)
+    else:
+        root_commit = None
 
     commit_time = datetime.now()
     author = gitconfig_user_get(gitconfig_read())
 
-    commit_map = create_commit_map(repo, root_commit)
+    if root_commit:
+        commit_map = create_commit_map(repo, root_commit)
+    else:
+        commit_map = dict()
 
     tree = tree_from_index(repo,
                            index,