diff --git a/tests/HTMLPurifier/AttrDef/IDTest.php b/tests/HTMLPurifier/AttrDef/IDTest.php
index 6e0e54be..e47ad9af 100644
--- a/tests/HTMLPurifier/AttrDef/IDTest.php
+++ b/tests/HTMLPurifier/AttrDef/IDTest.php
@@ -66,13 +66,11 @@ class HTMLPurifier_AttrDef_IDTest extends HTMLPurifier_AttrDefHarness
         $this->assertDef('user_story95_alas');
         $this->assertDef('user_alas', 'user_story95_user_alas'); // !
         
+        // no effect when IDPrefix isn't set
         $this->config->set('Attr', 'IDPrefix', '');
-        $this->assertDef('amherst'); // no affect when IDPrefix isn't set
-        $this->assertError('%Attr.IDPrefixLocal cannot be used unless '.
+        $this->expectError('%Attr.IDPrefixLocal cannot be used unless '.
             '%Attr.IDPrefix is set');
-        // SimpleTest has a bug and throws a sprintf error
-        // $this->assertNoErrors();
-        $this->swallowErrors();
+        $this->assertDef('amherst');
         
     }
     
diff --git a/tests/HTMLPurifier/ChildDef/StrictBlockquoteTest.php b/tests/HTMLPurifier/ChildDef/StrictBlockquoteTest.php
index a3e2cb14..27aacc81 100644
--- a/tests/HTMLPurifier/ChildDef/StrictBlockquoteTest.php
+++ b/tests/HTMLPurifier/ChildDef/StrictBlockquoteTest.php
@@ -38,10 +38,9 @@ extends HTMLPurifier_ChildDefHarness
         $this->assertResult('Needs wrap', '<div>Needs wrap</div>',
             array('HTML.BlockWrapper' => 'div'));
         
+        $this->expectError('Cannot use non-block element as block wrapper.');
         $this->assertResult('Needs wrap', '<p>Needs wrap</p>',
             array('HTML.BlockWrapper' => 'dav'));
-        $this->assertError('Cannot use non-block element as block wrapper.');
-        $this->assertNoErrors();
         
     }
     
diff --git a/tests/HTMLPurifier/ConfigSchemaTest.php b/tests/HTMLPurifier/ConfigSchemaTest.php
index 7c81d480..3102e1fd 100644
--- a/tests/HTMLPurifier/ConfigSchemaTest.php
+++ b/tests/HTMLPurifier/ConfigSchemaTest.php
@@ -71,12 +71,11 @@ class HTMLPurifier_ConfigSchemaTest extends UnitTestCase
         
         
         // define a directive in an undefined namespace
+        $this->expectError('Cannot define directive for undefined namespace');
         HTMLPurifier_ConfigSchema::define(
             'Extension', 'Name', false, 'bool',
             'This is for an extension, but we have not defined its namespace!'
         );
-        $this->assertError('Cannot define directive for undefined namespace');
-        $this->assertNoErrors();
         
         
         
@@ -86,7 +85,7 @@ class HTMLPurifier_ConfigSchemaTest extends UnitTestCase
             'Core', 'Name', 'default value', 'string',
             $description
         ); $line = __LINE__;
-        $this->assertNoErrors();
+        
         $directive->addDescription($file, $line, $description);
         $this->assertIdentical($this->our_copy->info, array(
             'Core' => array(
@@ -97,12 +96,11 @@ class HTMLPurifier_ConfigSchemaTest extends UnitTestCase
         
         
         // redefine a directive in an invalid manner
+        $this->expectError('Inconsistent default or type, cannot redefine');
         HTMLPurifier_ConfigSchema::define(
             'Core', 'Name', 'different default', 'string',
             'Inconsistent default or type, cannot redefine'
         );
-        $this->assertError('Inconsistent default or type, cannot redefine');
-        $this->assertNoErrors();
         
         
         
@@ -141,13 +139,12 @@ class HTMLPurifier_ConfigSchemaTest extends UnitTestCase
         
         
         // cannot define enumeration for undefined directive
+        $this->expectError('Cannot define allowed values for undefined directive');
         HTMLPurifier_ConfigSchema::defineAllowedValues(
             'Core', 'Foobar', array(
                 'Real Value 9',
             )
         );
-        $this->assertError('Cannot define allowed values for undefined directive');
-        $this->assertNoErrors();
         
         
         
@@ -182,47 +179,41 @@ class HTMLPurifier_ConfigSchemaTest extends UnitTestCase
         
         
         // cannot create alias to not-allowed value
+        $this->expectError('Cannot define alias to value that is not allowed');
         HTMLPurifier_ConfigSchema::defineValueAliases(
             'Core', 'Name', array(
                 'Aliased Value 3' => 'Invalid Value'
             )
         );
-        $this->assertError('Cannot define alias to value that is not allowed');
-        $this->assertNoErrors();
         
         
         
         // cannot create alias for already allowed value
+        $this->expectError('Cannot define alias over allowed value');
         HTMLPurifier_ConfigSchema::defineValueAliases(
             'Core', 'Name', array(
                 'Real Value' => 'Real Value 2'
             )
         );
-        $this->assertError('Cannot define alias over allowed value');
-        $this->assertNoErrors();
         
         
         
         // define a directive with an invalid type
+        $this->expectError('Invalid type for configuration directive');
         HTMLPurifier_ConfigSchema::define(
             'Core', 'Foobar', false, 'omen',
             'Omen is not a valid type, so we reject this.'
         );
         
-        $this->assertError('Invalid type for configuration directive');
-        $this->assertNoErrors();
-        
         
         
         // define a directive with inconsistent type
+        $this->expectError('Default value does not match directive type');
         HTMLPurifier_ConfigSchema::define(
             'Core', 'Foobaz', 10, 'string',
             'If we say string, we should mean it, not integer 10.'
         );
         
-        $this->assertError('Default value does not match directive type');
-        $this->assertNoErrors();
-        
         
         
         // define a directive that allows null
@@ -231,25 +222,22 @@ class HTMLPurifier_ConfigSchemaTest extends UnitTestCase
             'Nulls are allowed if you add on /null, cool huh?'
         );
         
-        $this->assertNoErrors();
         
         
         // define a directive with bad characters
+        $this->expectError('Directive name must be alphanumeric');
         HTMLPurifier_ConfigSchema::define(
             'Core', 'Core.Attr', 10, 'int',
             'No periods! >:-('
         );
         
-        $this->assertError('Directive name must be alphanumeric');
-        $this->assertNoErrors();
         
         // define a namespace with bad characters
+        $this->expectError('Namespace name must be alphanumeric');
         HTMLPurifier_ConfigSchema::defineNamespace(
             'Foobar&Gromit', $description
         );
         
-        $this->assertError('Namespace name must be alphanumeric');
-        $this->assertNoErrors();
         
         // alias related tests
         
diff --git a/tests/HTMLPurifier/ConfigTest.php b/tests/HTMLPurifier/ConfigTest.php
index e4634107..02e1628b 100644
--- a/tests/HTMLPurifier/ConfigTest.php
+++ b/tests/HTMLPurifier/ConfigTest.php
@@ -63,48 +63,39 @@ class HTMLPurifier_ConfigTest extends UnitTestCase
         $this->assertIdentical($config->get('Core', 'Key'), true);
         
         // try to retrieve undefined value
+        $this->expectError('Cannot retrieve value of undefined directive');
         $config->get('Core', 'NotDefined');
-        $this->assertError('Cannot retrieve value of undefined directive');
-        $this->assertNoErrors();
         
         // try to set undefined value
+        $this->expectError('Cannot set undefined directive to value');
         $config->set('Foobar', 'Key', 'foobar');
-        $this->assertError('Cannot set undefined directive to value');
-        $this->assertNoErrors();
         
         // try to set not allowed value
+        $this->expectError('Value not supported');
         $config->set('Extension', 'Pert', 'wizard');
-        $this->assertError('Value not supported');
-        $this->assertNoErrors();
         
         // try to set not allowed value
+        $this->expectError('Value is of invalid type');
         $config->set('Extension', 'Pert', 34);
-        $this->assertError('Value is of invalid type');
-        $this->assertNoErrors();
         
         // set aliased value
         $config->set('Extension', 'Pert', 'cow');
-        $this->assertNoErrors();
         $this->assertIdentical($config->get('Extension', 'Pert'), 'moo');
         
         // case-insensitive attempt to set value that is allowed
         $config->set('Core', 'Encoding', 'ISO-8859-1');
-        $this->assertNoErrors();
         $this->assertIdentical($config->get('Core', 'Encoding'), 'iso-8859-1');
         
         // set null to directive that allows null
         $config->set('Extension', 'CanBeNull', null);
-        $this->assertNoErrors();
         $this->assertIdentical($config->get('Extension', 'CanBeNull'), null);
         
         $config->set('Extension', 'CanBeNull', 'foobar');
-        $this->assertNoErrors();
         $this->assertIdentical($config->get('Extension', 'CanBeNull'), 'foobar');
         
         // set null to directive that doesn't allow null
+        $this->expectError('Value is of invalid type');
         $config->set('Extension', 'Pert', null);
-        $this->assertError('Value is of invalid type');
-        $this->assertNoErrors();
         
         // grab a namespace
         $config->set('Attr', 'Key', 0xBEEF);
@@ -116,9 +107,8 @@ class HTMLPurifier_ConfigTest extends UnitTestCase
         );
         
         // grab a non-existant namespace
+        $this->expectError('Cannot retrieve undefined namespace');
         $config->getBatch('FurnishedGoods');
-        $this->assertError('Cannot retrieve undefined namespace');
-        $this->assertNoErrors();
         
     }
     
diff --git a/tests/HTMLPurifier/ContextTest.php b/tests/HTMLPurifier/ContextTest.php
index 88c0f615..195a5030 100644
--- a/tests/HTMLPurifier/ContextTest.php
+++ b/tests/HTMLPurifier/ContextTest.php
@@ -29,12 +29,13 @@ class HTMLPurifier_ContextTest extends UnitTestCase
         
         $this->context->destroy('IDAccumulator');
         $this->assertFalse($this->context->exists('IDAccumulator'));
+        
+        $this->expectError('Attempted to retrieve non-existent variable');
         $accumulator_3 =& $this->context->get('IDAccumulator');
-        $this->assertError('Attempted to retrieve non-existent variable');
         $this->assertNull($accumulator_3);
         
+        $this->expectError('Attempted to destroy non-existent variable');
         $this->context->destroy('IDAccumulator');
-        $this->assertError('Attempted to destroy non-existent variable');
         
     }
     
@@ -42,15 +43,13 @@ class HTMLPurifier_ContextTest extends UnitTestCase
         
         $var = true;
         $this->context->register('OnceOnly', $var);
-        $this->assertNoErrors();
         
+        $this->expectError('Name collision, cannot re-register');
         $this->context->register('OnceOnly', $var);
-        $this->assertError('Name collision, cannot re-register');
         
         // destroy it, now registration is okay
         $this->context->destroy('OnceOnly');
         $this->context->register('OnceOnly', $var);
-        $this->assertNoErrors();
         
     }
     
diff --git a/tests/HTMLPurifier/Strategy/FixNestingTest.php b/tests/HTMLPurifier/Strategy/FixNestingTest.php
index a395cf07..38bd996b 100644
--- a/tests/HTMLPurifier/Strategy/FixNestingTest.php
+++ b/tests/HTMLPurifier/Strategy/FixNestingTest.php
@@ -91,11 +91,10 @@ class HTMLPurifier_Strategy_FixNestingTest extends HTMLPurifier_StrategyHarness
             '<div>Reject</div>', 'Reject', array('HTML.Parent' => 'span')
         );
         
+        $this->expectError('Cannot use unrecognized element as parent.');
         $this->assertResult(
             '<div>Accept</div>', true, array('HTML.Parent' => 'script')
         );
-        $this->assertError('Cannot use unrecognized element as parent.');
-        $this->assertNoErrors();
         
     }