diff --git a/src/fileio.c b/src/fileio.c
index 973e8ca..0f3f148 100644
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -10210,7 +10210,7 @@
     else
 	reg_pat[i++] = '^';
     endp = pat_end - 1;
-    if (*endp == '*')
+    if (endp >= pat && *endp == '*')
     {
 	while (endp - pat > 0 && *endp == '*')
 	    endp--;