diff --git a/ompi/mca/btl/openib/btl_openib_component.c b/ompi/mca/btl/openib/btl_openib_component.c
index 368bea2e5c..373e80caf7 100644
--- a/ompi/mca/btl/openib/btl_openib_component.c
+++ b/ompi/mca/btl/openib/btl_openib_component.c
@@ -27,6 +27,7 @@
 #include <infiniband/verbs.h>
 #include <errno.h>
 #include <string.h>   /* for strerror()*/
+#include <unistd.h>
 
 #include "ompi/constants.h"
 #include "opal/event/event.h"