diff --git a/sys/riscv/riscv/nexus.c b/sys/riscv/riscv/nexus.c
index a4ced760eea..75e16b881f1 100644
--- a/sys/riscv/riscv/nexus.c
+++ b/sys/riscv/riscv/nexus.c
@@ -242,7 +242,7 @@ nexus_alloc_resource(device_t bus, device_t child, int type, int *rid,
 	}
 
 	rv = rman_reserve_resource(rm, start, end, count, flags, child);
-	if (rv == 0)
+	if (rv == NULL)
 		return (NULL);
 
 	rman_set_rid(rv, *rid);