diff --git a/cpp/ycm/ClangCompleter/ClangUtils.cpp b/cpp/ycm/ClangCompleter/ClangUtils.cpp
index 14fcf48a..70f571d9 100644
--- a/cpp/ycm/ClangCompleter/ClangUtils.cpp
+++ b/cpp/ycm/ClangCompleter/ClangUtils.cpp
@@ -35,7 +35,9 @@ std::vector< CXUnsavedFile > ToCXUnsavedFiles(
   std::vector< CXUnsavedFile > clang_unsaved_files( unsaved_files.size() );
   for ( uint i = 0; i < unsaved_files.size(); ++i )
   {
-    // TODO: assert non-null
+    X_VERIFY( unsaved_files[ i ].filename_ );
+    X_VERIFY( unsaved_files[ i ].contents_ );
+    X_VERIFY( unsaved_files[ i ].length_ );
     clang_unsaved_files[ i ].Filename = unsaved_files[ i ].filename_;
     clang_unsaved_files[ i ].Contents = unsaved_files[ i ].contents_;
     clang_unsaved_files[ i ].Length   = unsaved_files[ i ].length_;