diff --git a/src/string_func.h b/src/string_func.h
index 8130f6db0e..2b117e4fed 100644
--- a/src/string_func.h
+++ b/src/string_func.h
@@ -26,6 +26,7 @@
 
 #include <stdarg.h>
 #include <iosfwd>
+#include <iterator>
 
 #include "core/bitmath_func.hpp"
 #include "core/span_type.hpp"