--- Math-BigInt-1.997/lib/Math/BigFloat.pm-	2011-09-03 10:28:57.000000000 +0400
+++ Math-BigInt-1.997/lib/Math/BigFloat.pm	2011-10-07 00:34:59.385558333 +0400
@@ -60,7 +60,7 @@ $upgrade = undef;
 $downgrade = undef;
 # the package we are using for our private parts, defaults to:
 # Math::BigInt->config()->{lib}
-my $MBI = 'Math::BigInt::Calc';
+my $MBI = 'Math::BigInt::FastCalc';
 
 # are NaNs ok? (otherwise it dies when encountering an NaN) set w/ config()
 $_trap_nan = 0;
--- Math-BigInt-1.997/lib/Math/BigInt.pm-	2011-09-03 10:26:41.000000000 +0400
+++ Math-BigInt-1.997/lib/Math/BigInt.pm	2011-10-07 00:35:34.614524562 +0400
@@ -172,7 +172,7 @@ $_trap_nan = 0;				# are NaNs ok? set w/
 $_trap_inf = 0;				# are infs ok? set w/ config()
 my $nan = 'NaN'; 			# constants for easier life
 
-my $CALC = 'Math::BigInt::Calc';	# module to do the low level math
+my $CALC = 'Math::BigInt::FastCalc';	# module to do the low level math
 					# default is Calc.pm
 my $IMPORT = 0;				# was import() called yet?
 					# used to make require work
@@ -2784,7 +2784,7 @@ sub import
     {
     $_ =~ tr/a-zA-Z0-9://cd;			# limit to sane characters
     }
-  push @c, \'Calc'				# if all fail, try these
+  push @c, \'FastCalc', \'Calc'			# if all fail, try these
     if $warn_or_die < 2;			# but not for "only"
   $CALC = '';					# signal error
   foreach my $l (@c)