diff --git a/src/sfizz/ScopedFTZ.h b/src/sfizz/ScopedFTZ.h
index 16196d5b..6fea43b0 100644
--- a/src/sfizz/ScopedFTZ.h
+++ b/src/sfizz/ScopedFTZ.h
@@ -4,6 +4,8 @@
 // license. You should have receive a LICENSE.md file along with the code.
 // If not, contact the sfizz maintainers at https://github.com/sfztools/sfizz
 
+#pragma once
+
 /**
  * @brief Flush floating points to zero and disable denormals as an RAII helper.
  *