diff --git a/components/misc/stringops.hpp b/components/misc/stringops.hpp
index 112d66bb8..029b617e1 100644
--- a/components/misc/stringops.hpp
+++ b/components/misc/stringops.hpp
@@ -1,6 +1,7 @@
 #ifndef MISC_STRINGOPS_H
 #define MISC_STRINGOPS_H
 
+#include <cctype>
 #include <string>
 #include <algorithm>