diff --git a/compar.c b/compar.c
index 65def78..7615bde 100644
--- a/compar.c
+++ b/compar.c
@@ -54,6 +54,9 @@ cmp_failed(void)
  *  Compares two objects based on the receiver's <code><=></code>
  *  method, returning true if it returns 0. Also returns true if
  *  _obj_ and _other_ are the same object.
+ *
+ *  If raising exception in evaluating _obj_ <=> _other_, exception
+ *  is rescued and returns false.
  */
 
 static VALUE
