diff --git a/app/models/commit.rb b/app/models/commit.rb
index f90c4267..263e2f74 100644
--- a/app/models/commit.rb
+++ b/app/models/commit.rb
@@ -120,10 +120,10 @@ class Commit
   end
 
   def prev_commit
-    parents.first
+    parents.try :first
   end
 
   def prev_commit_id
-    prev_commit.id
+    prev_commit.try :id
   end
 end