diff --git a/include/internal/catch_tostring.hpp b/include/internal/catch_tostring.hpp
index d5714e8d..cec4cfed 100644
--- a/include/internal/catch_tostring.hpp
+++ b/include/internal/catch_tostring.hpp
@@ -14,6 +14,7 @@
 #include <sstream>
 #include <iomanip>
 #include <limits>
+#include <vector>
 
 #ifdef __OBJC__
 #include "catch_objc_arc.hpp"