diff --git a/util/include/rusefi/rusefi_time_math.h b/util/include/rusefi/rusefi_time_math.h
index 6fdbd34..81ea802 100644
--- a/util/include/rusefi/rusefi_time_math.h
+++ b/util/include/rusefi/rusefi_time_math.h
@@ -1,3 +1,4 @@
+#pragma once
 
 #include <global.h>
 #include <rusefi/rusefi_time_types.h>