diff --git a/catch_runner.hpp b/catch_runner.hpp
index 03e183c5..22f08637 100644
--- a/catch_runner.hpp
+++ b/catch_runner.hpp
@@ -22,6 +22,7 @@
 #include "catch_reporter_junit.hpp"
 
 #include <fstream>
+#include <stdlib.h>
 
 namespace Catch
 {
diff --git a/internal/catch_generators.hpp b/internal/catch_generators.hpp
index a6167a4e..ccb6b6d4 100644
--- a/internal/catch_generators.hpp
+++ b/internal/catch_generators.hpp
@@ -15,8 +15,10 @@
 
 #include "catch_hub.h"
 
+#include <iterator>
 #include <vector>
 #include <string>
+#include <stdlib.h>
 
 namespace Catch
 {
diff --git a/internal/catch_hub.h b/internal/catch_hub.h
index 374b245b..08983003 100644
--- a/internal/catch_hub.h
+++ b/internal/catch_hub.h
@@ -12,10 +12,11 @@
 #ifndef TWOBLUECUBES_CATCH_HUB_H_INCLUDED
 #define TWOBLUECUBES_CATCH_HUB_H_INCLUDED
 
+#include "catch_interfaces_reporter.h"
+
 #include <memory>
 #include <vector>
-
-#include "catch_interfaces_reporter.h"
+#include <stdlib.h>
 
 namespace Catch
 {