diff --git a/lib/jpegli/libjpeg_test_util.cc b/lib/jpegli/libjpeg_test_util.cc
index c9a03fed..051b5d6a 100644
--- a/lib/jpegli/libjpeg_test_util.cc
+++ b/lib/jpegli/libjpeg_test_util.cc
@@ -6,6 +6,7 @@
 
 #include "lib/jpegli/libjpeg_test_util.h"
 
+#include <cstdlib>
 #include <cstring>
 
 #include "lib/base/include_jpeglib.h"  // NOLINT