diff --git a/src/3rdParty/FastSignals/libfastsignals/include/fastsignals/function_detail.h b/src/3rdParty/FastSignals/libfastsignals/include/fastsignals/function_detail.h
index 3b41170b50..033f607a4b 100644
--- a/src/3rdParty/FastSignals/libfastsignals/include/fastsignals/function_detail.h
+++ b/src/3rdParty/FastSignals/libfastsignals/include/fastsignals/function_detail.h
@@ -1,6 +1,7 @@
 #pragma once
 
 #include <cassert>
+#include <cstddef>
 #include <cstdint>
 #include <type_traits>
 #include <utility>