diff --git a/clang/include/clang/Rewrite/DeltaTree.h b/clang/include/clang/Rewrite/DeltaTree.h
index 7e0796524c6d..f32906a323e0 100644
--- a/clang/include/clang/Rewrite/DeltaTree.h
+++ b/clang/include/clang/Rewrite/DeltaTree.h
@@ -17,7 +17,7 @@
 namespace clang {
 
   /// DeltaTree - a multiway search tree (BTree) structure with some fancy
-  /// features.  B-Trees are are generally more memory and cache efficient than
+  /// features.  B-Trees are generally more memory and cache efficient than
   /// binary trees, because they store multiple keys/values in each node.  This
   /// implements a key/value mapping from index to delta, and allows fast lookup
   /// on index.  However, an added (important) bonus is that it can also
diff --git a/clang/lib/Rewrite/DeltaTree.cpp b/clang/lib/Rewrite/DeltaTree.cpp
index 101cf93f9db9..35e888bcf595 100644
--- a/clang/lib/Rewrite/DeltaTree.cpp
+++ b/clang/lib/Rewrite/DeltaTree.cpp
@@ -20,7 +20,7 @@ using llvm::cast;
 using llvm::dyn_cast;
 
 /// The DeltaTree class is a multiway search tree (BTree) structure with some
-/// fancy features.  B-Trees are are generally more memory and cache efficient
+/// fancy features.  B-Trees are generally more memory and cache efficient
 /// than binary trees, because they store multiple keys/values in each node.
 ///
 /// DeltaTree implements a key/value mapping from FileIndex to Delta, allowing