diff --git a/src/edit.c b/src/edit.c
index b4e6767..9cc55ef 100644
--- a/src/edit.c
+++ b/src/edit.c
@@ -2197,7 +2197,7 @@
 	    i -= middle_len;
 
 	    // Check some expected things before we go on
-	    if (i >= 0 && lead_end[end_len - 1] == end_comment_pending)
+	    if (i >= 0 && end_len > 0 && lead_end[end_len - 1] == end_comment_pending)
 	    {
 		// Backspace over all the stuff we want to replace
 		backspace_until_column(i);