diff --git a/src/insexpand.c b/src/insexpand.c
index 7339ce9..fc3eff0 100644
--- a/src/insexpand.c
+++ b/src/insexpand.c
@@ -3501,7 +3501,7 @@
     {
 	char_u	*tmp_ptr = ptr;
 
-	if (compl_status_adding())
+	if (compl_status_adding() && compl_length <= (int)STRLEN(tmp_ptr))
 	{
 	    tmp_ptr += compl_length;
 	    // Skip if already inside a word.