diff --git a/libs/gltfio/src/TangentsJob.cpp b/libs/gltfio/src/TangentsJob.cpp
index 8194fb5c76..421ff166bf 100644
--- a/libs/gltfio/src/TangentsJob.cpp
+++ b/libs/gltfio/src/TangentsJob.cpp
@@ -16,6 +16,7 @@
 
 #include "TangentsJob.h"
 
+#include <cstdlib>
 #include <memory>
 
 #include <geometry/SurfaceOrientation.h>