diff --git a/include/string_span.h b/include/string_span.h
index c9a4dc9..686ace9 100644
--- a/include/string_span.h
+++ b/include/string_span.h
@@ -23,6 +23,7 @@
 #include "gsl_util.h"
 #include "span.h"
 #include <cstring>
+#include <string>
 
 #ifdef _MSC_VER