diff --git a/include/jwt/impl/jwt.ipp b/include/jwt/impl/jwt.ipp
index 01b0881..1797f4c 100644
--- a/include/jwt/impl/jwt.ipp
+++ b/include/jwt/impl/jwt.ipp
@@ -26,6 +26,7 @@ SOFTWARE.
 #include "jwt/config.hpp"
 #include "jwt/detail/meta.hpp"
 #include <algorithm>
+#include <iomanip>
 
 namespace jwt {