diff --git a/src/hb-aat-layout-morx-table.hh b/src/hb-aat-layout-morx-table.hh
index 0a2d62b..a8b287f 100644
--- a/src/hb-aat-layout-morx-table.hh
+++ b/src/hb-aat-layout-morx-table.hh
@@ -608,7 +608,7 @@
       hb_buffer_t *buffer = driver->buffer;
       unsigned int flags = entry->flags;
 
-      if (entry->data.markedInsertIndex != 0xFFFF)
+      if (entry->data.markedInsertIndex != 0xFFFF && mark_set)
       {
 	unsigned int count = (flags & MarkedInsertCount);
 	unsigned int start = entry->data.markedInsertIndex;
@@ -617,8 +617,6 @@
 
 	bool before = flags & MarkedInsertBefore;
 
-	if (unlikely (!mark_set)) return false;
-
 	unsigned int end = buffer->out_len;
 	buffer->move_to (mark);