diff --git a/Testing/Utilities/openthreadsSimpleThreader.cpp b/Testing/Utilities/openthreadsSimpleThreader.cpp
index 4e9aa4acbafebe2bd1e29de2cbffb944651e3fc1..e4eb659d15c178bfe399b94b286741a1979d617e 100755
--- a/Testing/Utilities/openthreadsSimpleThreader.cpp
+++ b/Testing/Utilities/openthreadsSimpleThreader.cpp
@@ -19,6 +19,7 @@
 #include <sys/types.h>
 #include <cassert>
 #include <cstdio>
+#include <cstdlib>
 #include <iostream>
 #include <vector>
 #include <OpenThreads/Thread>
diff --git a/Testing/Utilities/openthreadsWorkCrew.cpp b/Testing/Utilities/openthreadsWorkCrew.cpp
index f997dab3e6dc31a1739605b586c28909d16e3e63..e273d99813465d620a181a8def97d2e678cd7db5 100755
--- a/Testing/Utilities/openthreadsWorkCrew.cpp
+++ b/Testing/Utilities/openthreadsWorkCrew.cpp
@@ -29,6 +29,7 @@
 #endif
 
 #include <iostream>
+#include <stdlib.h>
 #include <vector>
 #include <cassert>
 #include <cerrno>