1 files changed, 3 insertions, 0 deletions
diff --git a/refclock_shm.c b/refclock_shm.c
index e8f6256..ed68095 100644
--- a/refclock_shm.c
+++ b/refclock_shm.c
@@ -59,10 +59,13 @@ struct shmTime {
 };
 
 static int shm_initialise(RCL_Instance instance) {
+  const char *options[] = {"perm", NULL};
   int id, param, perm;
   char *s;
   struct shmTime *shm;
 
+  RCL_CheckDriverOptions(instance, options);
+
   param = atoi(RCL_GetDriverParameter(instance));
   s = RCL_GetDriverOption(instance, "perm");
   perm = s ? strtol(s, NULL, 8) & 0777 : 0600;