diff --git a/include/sfun/string_utils.h b/include/sfun/string_utils.h
index 64095fe..c1b0a2a 100644
--- a/include/sfun/string_utils.h
+++ b/include/sfun/string_utils.h
@@ -3,6 +3,7 @@
 
 #include <algorithm>
 #include <cctype>
+#include <iterator>
 #include <string>
 #include <string_view>
 #include <vector>