diff --git a/toml/parser.hpp b/toml/parser.hpp
index f5e3197..bba80fd 100644
--- a/toml/parser.hpp
+++ b/toml/parser.hpp
@@ -5,6 +5,7 @@
 #include <algorithm>
 #include <iostream>
 #include <fstream>
+#include <sstream>
 
 namespace toml
 {