diff --git a/LibGit2Sharp/Core/FileHistory.cs b/LibGit2Sharp/Core/FileHistory.cs
index 5775d0ab8..9f3b4e9fd 100644
--- a/LibGit2Sharp/Core/FileHistory.cs
+++ b/LibGit2Sharp/Core/FileHistory.cs
@@ -163,6 +163,16 @@ private static void DetermineParentPaths(IRepository repo, Commit currentCommit,
 
         private static string ParentPath(IRepository repo, Commit currentCommit, string currentPath, Commit parentCommit)
         {
+            // optimization: if the SHA of the parent commit's TreeEntry is the same as this commit's TreeEntry then
+            // they are the same and there is no need to diff the commit
+            TreeEntry parentTreeEntry = parentCommit.Tree[currentPath];
+            TreeEntry thisTreeEntry = currentCommit.Tree[currentPath];
+            if (parentTreeEntry != null && parentTreeEntry.Target.Sha == thisTreeEntry.Target.Sha)
+            {
+                return currentPath;
+            }
+
+            // something in the tree is different, so we need to diff the commits to look for renames
             using (var treeChanges = repo.Diff.Compare<TreeChanges>(parentCommit.Tree, currentCommit.Tree))
             {
                 var treeEntryChanges = treeChanges.FirstOrDefault(c => c.Path == currentPath);
diff --git a/LibGit2Sharp/Tree.cs b/LibGit2Sharp/Tree.cs
index 30f534a99..45afaddb4 100644
--- a/LibGit2Sharp/Tree.cs
+++ b/LibGit2Sharp/Tree.cs
@@ -43,6 +43,8 @@ internal Tree(Repository repo, ObjectId id, string path)
         /// <exception cref="NotFoundException">Throws if tree is missing</exception>
         public virtual int Count => lazyCount.Value;
 
+        private Dictionary<string, TreeEntry> _treeCache;
+
         /// <summary>
         /// Gets the <see cref="TreeEntry"/> pointed at by the <paramref name="relativePath"/> in this <see cref="Tree"/> instance.
         /// </summary>
@@ -51,9 +53,19 @@ internal Tree(Repository repo, ObjectId id, string path)
         /// <exception cref="NotFoundException">Throws if tree is missing</exception>
         public virtual TreeEntry this[string relativePath]
         {
-            get { return RetrieveFromPath(relativePath); }
+            get
+            {
+                TreeEntry ret;
+                if (_treeCache == null) _treeCache = new Dictionary<string, TreeEntry>();
+                else if (_treeCache.TryGetValue(relativePath, out ret)) return ret;
+
+                ret = RetrieveFromPath(relativePath);
+                _treeCache[relativePath] = ret;
+                return ret;
+            }
         }
 
+
         private unsafe TreeEntry RetrieveFromPath(string relativePath)
         {
             if (string.IsNullOrEmpty(relativePath))