diff --git a/src/cressi_edy.c b/src/cressi_edy.c
index 96155ef..67ca985 100644
--- a/src/cressi_edy.c
+++ b/src/cressi_edy.c
@@ -374,6 +374,8 @@ cressi_edy_device_foreach (device_t *abstract, dive_callback_t callback, void *u
 	unsigned int first = config[0x7D];
 	if (first < RB_LOGBOOK_BEGIN || first >= RB_LOGBOOK_END ||
 		last < RB_LOGBOOK_BEGIN || last >= RB_LOGBOOK_END) {
+		if (last == 0xFF)
+			return DEVICE_STATUS_SUCCESS;
 		WARNING ("Invalid ringbuffer pointer detected.");
 		return DEVICE_STATUS_ERROR;
 	}
diff --git a/src/zeagle_n2ition3.c b/src/zeagle_n2ition3.c
index 0aaf71d..8495788 100644
--- a/src/zeagle_n2ition3.c
+++ b/src/zeagle_n2ition3.c
@@ -310,6 +310,8 @@ zeagle_n2ition3_device_foreach (device_t *abstract, dive_callback_t callback, vo
 	unsigned int first = config[0x7D];
 	if (first < RB_LOGBOOK_BEGIN || first >= RB_LOGBOOK_END ||
 		last < RB_LOGBOOK_BEGIN || last >= RB_LOGBOOK_END) {
+		if (last == 0xFF)
+			return DEVICE_STATUS_SUCCESS;
 		WARNING ("Invalid ringbuffer pointer detected.");
 		return DEVICE_STATUS_ERROR;
 	}