diff --git a/src/netanim/test/netanim-test.cc b/src/netanim/test/netanim-test.cc
index e9d1a0401..633dbe4f9 100644
--- a/src/netanim/test/netanim-test.cc
+++ b/src/netanim/test/netanim-test.cc
@@ -17,6 +17,7 @@
  */
 
 #include <iostream>
+#include "unistd.h"
 
 #include "ns3/core-module.h"
 #include "ns3/network-module.h"