diff --git a/clang/tools/libclang/CIndex.cpp b/clang/tools/libclang/CIndex.cpp
index 554edd824ef0b5e3d5d48e5017021baac81d2370..f41906209d1dfee070eca9dfc5821793c0a14785 100644
--- a/clang/tools/libclang/CIndex.cpp
+++ b/clang/tools/libclang/CIndex.cpp
@@ -1965,7 +1965,8 @@ CXTranslationUnit clang_createTranslationUnit(CXIndex CIdx,
 }
 
 unsigned clang_defaultEditingTranslationUnitOptions() {
-  return CXTranslationUnit_PrecompiledPreamble;
+  return CXTranslationUnit_PrecompiledPreamble | 
+         CXTranslationUnit_CacheCompletionResults;
 }
   
 CXTranslationUnit