diff -u Math-BigInt-1.997/lib/Math/BigInt.pm Math-BigInt-1.997-r1/lib/Math/BigInt.pm
--- Math-BigInt-1.997/lib/Math/BigInt.pm	2011-09-03 02:26:41.000000000 -0400
+++ Math-BigInt-1.997-r1/lib/Math/BigInt.pm	2012-07-17 20:32:26.630203065 -0400
@@ -40,6 +40,9 @@
 # Thus inheritance of overload operators becomes possible and transparent for
 # our subclasses without the need to repeat the entire overload section there.
 
+# https://github.com/ilmari/perl/commit/5e0688b6067afdfb59fdfa9923e658ed40c9f246
+# We register ops that are not registerable yet, so suppress warnings
+{ no warnings;
 use overload
 '='     =>      sub { $_[0]->copy(); },
 
@@ -151,6 +154,7 @@
 '""' => sub { $_[0]->bstr(); },
 '0+' => sub { $_[0]->numify(); }
 ;
+} # no warnings scope
 
 ##############################################################################
 # global constants, flags and accessory