diff --git a/Graphics/Limits/t/limits_range.t b/Graphics/Limits/t/limits_range.t
index ab50e26ca..4fc1c90e8 100644
--- a/Graphics/Limits/t/limits_range.t
+++ b/Graphics/Limits/t/limits_range.t
@@ -1,6 +1,7 @@
 use strict;
 use warnings;
 use Test::More;
+use Test::PDL;
 use PDL;
 use PDL::Graphics::Limits;
 
@@ -34,7 +35,7 @@ $x1 = pdl( 1, 2, 3, 4 );
 $y1 = pdl( 0, 10, 3, 4 );
 
 @range = limits( [ $x1, $y1 ], { Bounds => 'Zscale', Clean => 'None' } );
-ok( all(approx( pdl(@range), pdl ( 1, 4, -0.4, 8.9 ) )), 'Zscale, None' ) or diag explain \@range;
+is_pdl pdl(@range), pdl(1, 4, -0.4, 8.9), 'Zscale, None';
 
 @range = limits( [ 1, 2 ], [ 3, 4 ], { Bounds => 'MinMax', Clean => 'None' } );
 is_deeply \@range, [ 1, 3, 2, 4 ], "scalars in the mix " or diag explain \@range;
diff --git a/Graphics/Limits/t/limits_round.t b/Graphics/Limits/t/limits_round.t
index eea8c6a3a..d5870885f 100644
--- a/Graphics/Limits/t/limits_round.t
+++ b/Graphics/Limits/t/limits_round.t
@@ -2,6 +2,7 @@ use strict;
 use warnings;
 use PDL::LiteF;
 use Test::More;
+use Test::PDL;
 use PDL::Graphics::Limits;
 use Config;
 
@@ -55,11 +56,10 @@ my @round_tests =
 
 for my $test ( @round_tests )
 {
-  my $down = round_pow( down => $test->[0] );
-  my $up   = round_pow( up   => $test->[0] );
-  my $eps  = abs($test->[0]) > 1 ? abs($test->[0])/1.0e-6 : 1.0e-6;
-
-  ok( approx($test->[1],$down,$eps) && approx($test->[2],$up,$eps), 'round_pow('. $test->[0] .')' );
+  my $down = pdl round_pow( down => $test->[0] );
+  my $up   = pdl round_pow( up   => $test->[0] );
+  is_pdl $down, pdl($test->[1]), "round_pow($test->[0])";
+  is_pdl $up, pdl($test->[2]), "round_pow($test->[0])";
 }
 
 done_testing;
diff --git a/Graphics/Limits/t/limits_trans_err.t b/Graphics/Limits/t/limits_trans_err.t
index 3a193849d..715c56652 100644
--- a/Graphics/Limits/t/limits_trans_err.t
+++ b/Graphics/Limits/t/limits_trans_err.t
@@ -1,6 +1,7 @@
 use strict;
 use warnings;
 use Test::More;
+use Test::PDL;
 use PDL;
 use PDL::Graphics::Limits;
 
@@ -16,18 +17,18 @@ my $y2 = pdl( -1, 2, 4 );
 my @udsets = ( [ [ $x1, $xn ], $y1], [ $x2, $y2 ] );
 my $range = pdl limits( @udsets, { Bounds => 'MinMax', Clean => 'None', Trans => [ \&log10 ], } );
 
-ok all(approx($range, pdl([ log10(1-0.5), log10(4), -1, 10 ]))), 'x symmetric trans';
+is_pdl $range, pdl([ log10(1-0.5), log10(4), -1, 10 ]), 'x symmetric trans';
 
 @udsets = ( [ [ $x1, $xn ], $y1], [ [ $x2, undef, $xp ], $y2 ] );
 $range = pdl limits( @udsets, { Bounds => 'MinMax', Clean => 'None', Trans => [ \&log10 ], } );
 
-ok all(approx($range, pdl([ log10(1-0.5), log10(4+0.25), -1, 10 ]))), 'x asymmetric trans';
+is_pdl $range, pdl([ log10(1-0.5), log10(4+0.25), -1, 10 ]), 'x asymmetric trans';
 
 $y1 = pdl( 0.5, 1, 5 );
 $y2 = pdl( 0.5, 0.5, 0.5 );
 @udsets = ( [ [ $y1, $y2 ] ] );
 $range = pdl limits( @udsets, { Bounds => 'MinMax', Clean => 'None', Trans => [ \&log10 ], } );
 
-ok all(approx($range, pdl([ log10(0.5), log10(5+0.5) ]))), 'illegal errbar lower bounds';
+is_pdl $range, pdl([ log10(0.5), log10(5+0.5) ]), 'illegal errbar lower bounds';
 
 done_testing;
diff --git a/Graphics/Limits/t/limits_ulimits.t b/Graphics/Limits/t/limits_ulimits.t
index 0fc48ac32..9e858a90f 100644
--- a/Graphics/Limits/t/limits_ulimits.t
+++ b/Graphics/Limits/t/limits_ulimits.t
@@ -1,6 +1,7 @@
 use strict;
 use warnings;
 use Test::More;
+use Test::PDL;
 use PDL;
 use PDL::Graphics::Limits;
 
@@ -84,7 +85,7 @@ my @tests = (
 foreach my $test ( @tests ) {
   my ( $msg, $limits, $exp ) = @$test;
   my $range = pdl limits( @udsets_arr, { %attr, Limits => $limits } );
-  ok( all(approx $range, pdl $exp), "array: $msg" );
+  is_pdl $range, pdl($exp), "array: $msg";
 }
 
 @tests = ( 
@@ -133,7 +134,7 @@ foreach my $test ( @tests ) {
 foreach my $test ( @tests ) {
   my ( $msg, $limits, $exp ) = @$test;
   my $range = pdl limits( @udsets_hash, { %attr, Limits => $limits,  VecKeys => [ qw/ x y / ] } );
-  ok( all(approx $range, pdl $exp), "hash: $msg" );
+  is_pdl $range, pdl($exp), "hash: $msg";
 }
 
 #############################################################
@@ -189,7 +190,7 @@ foreach my $test ( @tests ) {
 foreach my $test ( @tests ) {
   my ( $msg, $limits, $exp ) = @$test;
   my $range = pdl limits( @udsets_arr, { %attr, Limits => $limits } );
-  ok( all(approx $range, pdl $exp), "array: $msg" ) or diag "($range), [@$exp]\n";
+  is_pdl $range, pdl($exp), "array: $msg";
 }
 
 done_testing;