diff --git a/src/afs/HPUX/osi_machdep.h b/src/afs/HPUX/osi_machdep.h
index bae87fe60f..1d138fc3e4 100644
--- a/src/afs/HPUX/osi_machdep.h
+++ b/src/afs/HPUX/osi_machdep.h
@@ -20,6 +20,7 @@
 #define _OSI_MACHDEP_H_
 
 #include "h/kern_sem.h"
+#include "h/proc_iface.h"
 
 #define	afs_hz	    hz
 extern struct timeval time;