diff --git a/src/zm_local_camera.cpp b/src/zm_local_camera.cpp
index 0679a5c5e..7d16c0015 100644
--- a/src/zm_local_camera.cpp
+++ b/src/zm_local_camera.cpp
@@ -24,6 +24,7 @@
 #include <fcntl.h>
 #include <sys/mman.h>
 #include <sys/stat.h>
+#include <unistd.h>
 
 #if ZM_HAS_V4L