diff --git a/.clang-format b/.clang-format
index 616348ec..f6f94c96 100644
--- a/.clang-format
+++ b/.clang-format
@@ -19,6 +19,10 @@ BinPackParameters: false
 BreakBeforeBinaryOperators: All
 PackConstructorInitializers: NextLine
 IncludeCategories:
+  - Regex: 'testlib\.h'
+    Priority: 1
+    SortPriority: 0
+    CaseSensitive: false
   - Regex: '^<(iostream|cstdio)>'
     Priority: 2
     SortPriority: 1