diff --git a/src/pv/watchpid.c b/src/pv/watchpid.c
index faddbd4..cbc1d2b 100644
--- a/src/pv/watchpid.c
+++ b/src/pv/watchpid.c
@@ -559,7 +559,7 @@ int pv_watchpid_scanfds(pvstate_t state, pid_t watch_pid, int watch_fd, int *arr
 #else
 	nullable_string_ptr fd_dir = NULL;
 	DIR *dptr;
-	struct dirent *d;
+	const struct dirent *d;
 
 	if ((pv_asprintf(&fd_dir, "/proc/%u/fd", watch_pid) < 0) || (NULL == fd_dir)) {
 		pv_perror("%s %u", _("pid"), watch_pid);