diff --git a/polly/CMakeLists.txt b/polly/CMakeLists.txt
index 8ccc5fb35d07..b6309acd2fbb 100644
--- a/polly/CMakeLists.txt
+++ b/polly/CMakeLists.txt
@@ -176,14 +176,14 @@ set(update_format_depends)
 set(i 0)
 foreach (file IN LISTS files)
   add_custom_command(OUTPUT polly-check-format${i}
-    COMMAND clang-format -style=llvm ${file} | diff -u ${file} -
+    COMMAND clang-format -sort-includes -style=llvm ${file} | diff -u ${file} -
     VERBATIM
     COMMENT "Checking format of ${file}..."
   )
   list(APPEND check_format_depends "polly-check-format${i}")
 
   add_custom_command(OUTPUT polly-update-format${i}
-    COMMAND clang-format -i -style=llvm ${file}
+    COMMAND clang-format -sort-includes -i -style=llvm ${file}
     VERBATIM
     COMMENT "Updating format of ${file}..."
   )