diff --git a/procname.c b/procname.c
index 1928b92e..1518c94b 100644
--- a/procname.c
+++ b/procname.c
@@ -17,6 +17,7 @@
  */
 
 #include <sys/param.h>
+#include <sys/proc.h>
 #include <sys/sysctl.h>
 #include <sys/stat.h>