diff --git a/bin/mimp b/bin/mimp
index 1ee08543..ba996793 100755
--- a/bin/mimp
+++ b/bin/mimp
@@ -12,7 +12,7 @@ use Config;
 use strict;
 use Getopt::Long;
 # External modules #
-use Math::Random;
+use random;
 # PsN includes #
 use PsN;
 use common_options;
diff --git a/bin/xv_scm b/bin/xv_scm
index 02e2b26f..8ea5b693 100755
--- a/bin/xv_scm
+++ b/bin/xv_scm
@@ -7,7 +7,7 @@ use lib "$Bin/../lib";
 # Everything above this line will be replaced #
 
 use PsN;
-use Math::Random;
+use random;
 use strict;
 use Getopt::Long;
 use Cwd;
diff --git a/lib/random.pm b/lib/random.pm
index 2917b2dd..3b8792ec 100644
--- a/lib/random.pm
+++ b/lib/random.pm
@@ -4,7 +4,7 @@ use strict;
 use Exporter qw(import);
 use PsN;
 
-our @EXPORT = qw(random_set_seed_from_phrase random_uniform_integer);
+our @EXPORT = qw(random_set_seed_from_phrase random_uniform_integer random_permuted_index);
 
 our $old;
 
@@ -37,4 +37,14 @@ sub random_uniform_integer
 }
 
 
+sub random_permuted_index
+{
+    if ($old) {
+        return Math::Random::random_permuted_index(@_); 
+    } else {
+        return Math::Random::Free::random_permuted_index(@_);
+    }
+}
+
+
 1;
diff --git a/lib/tool/gls.pm b/lib/tool/gls.pm
index 08125078..4e0739de 100644
--- a/lib/tool/gls.pm
+++ b/lib/tool/gls.pm
@@ -2,7 +2,7 @@ package tool::gls;
 
 use include_modules;
 use tool::modelfit;
-use Math::Random;
+use random;
 use Config;
 use Mouse;
 use MouseX::Params::Validate;
diff --git a/lib/tool/mcmp.pm b/lib/tool/mcmp.pm
index 365e9a3d..0ab478d1 100644
--- a/lib/tool/mcmp.pm
+++ b/lib/tool/mcmp.pm
@@ -1,7 +1,7 @@
 package tool::mcmp;
 
 use include_modules;
-use Math::Random;
+use random;
 use strict;
 use tool::modelfit;
 use model;
diff --git a/lib/tool/nonpb.pm b/lib/tool/nonpb.pm
index cf64420d..595860c1 100644
--- a/lib/tool/nonpb.pm
+++ b/lib/tool/nonpb.pm
@@ -1,7 +1,7 @@
 package tool::nonpb;
 
 use include_modules;
-use Math::Random;
+use random;
 use strict;
 use tool::modelfit;
 use tool::pind;
diff --git a/lib/tool/npc.pm b/lib/tool/npc.pm
index 7a0f699a..857be155 100644
--- a/lib/tool/npc.pm
+++ b/lib/tool/npc.pm
@@ -1,7 +1,7 @@
 package tool::npc;
 
 use include_modules;
-use Math::Random;
+use random;
 use strict;
 use tool::modelfit;
 use model;
diff --git a/lib/tool/pvar.pm b/lib/tool/pvar.pm
index 8374f67e..34201ce0 100644
--- a/lib/tool/pvar.pm
+++ b/lib/tool/pvar.pm
@@ -1,7 +1,7 @@
 package tool::pvar;
 
 use include_modules;
-use Math::Random;
+use random;
 use File::Spec;
 use Mouse;
 use MouseX::Params::Validate;
diff --git a/lib/tool/qa.pm b/lib/tool/qa.pm
index 55c55c62..44e12225 100644
--- a/lib/tool/qa.pm
+++ b/lib/tool/qa.pm
@@ -1,7 +1,7 @@
 package tool::qa;
 
 use strict;
-use Math::Random;
+use random;
 use Mouse;
 use MouseX::Params::Validate;
 use File::Copy 'cp';