diff --git a/src/json-uri.cpp b/src/json-uri.cpp
index 5b737d3..6a3136f 100644
--- a/src/json-uri.cpp
+++ b/src/json-uri.cpp
@@ -25,6 +25,8 @@
  */
 #include "json-schema.hpp"
 
+#include <sstream>
+
 namespace nlohmann
 {