diff --git a/clang/include/clang/Lex/HeaderSearch.h b/clang/include/clang/Lex/HeaderSearch.h
index d1cb8118c0c3..d3b3193572af 100644
--- a/clang/include/clang/Lex/HeaderSearch.h
+++ b/clang/include/clang/Lex/HeaderSearch.h
@@ -191,12 +191,15 @@ class HeaderSearch {
     /// Starting index in SearchDirs that the cached search was performed from.
     /// If there is a hit and this value doesn't match the current query, the
     /// cache has to be ignored.
-    unsigned StartIdx = 0;
+    unsigned StartIdx;
     /// The entry in SearchDirs that satisfied the query.
-    unsigned HitIdx = 0;
+    unsigned HitIdx;
     /// This is non-null if the original filename was mapped to a framework
     /// include via a headermap.
-    const char *MappedName = nullptr;
+    const char *MappedName;
+
+    /// Default constructor -- Initialize all members with zero.
+    LookupFileCacheInfo(): StartIdx(0), HitIdx(0), MappedName(nullptr) {}
   };
   llvm::StringMap<LookupFileCacheInfo, llvm::BumpPtrAllocator> LookupFileCache;