diff --git a/src/session.c b/src/session.c
index 24acb71..2a1fdb3 100644
--- a/src/session.c
+++ b/src/session.c
@@ -3337,7 +3337,7 @@
 
 	smp->flags = SMP_F_VOL_TEST;
 	smp->type = SMP_T_UINT;
-	smp->data.uint = stkctr_entry(stkctr)->ref_cnt;
+	smp->data.uint = stkctr_entry(stkctr) ? stkctr_entry(stkctr)->ref_cnt : 0;
 	return 1;
 }