diff --git a/src/realm/util/cli_args.cpp b/src/realm/util/cli_args.cpp
index a199b2e214..69421d6b47 100644
--- a/src/realm/util/cli_args.cpp
+++ b/src/realm/util/cli_args.cpp
@@ -1,6 +1,7 @@
 #include "realm/util/cli_args.hpp"
 
 #include <algorithm>
+#include <cstdlib>
 #include <cerrno>
 #include <cstdint>
 #include <string>