diff --git a/library/HTMLPurifier/AttrTransform/TargetBlank.php b/library/HTMLPurifier/AttrTransform/TargetBlank.php
index a6502c74..deba8b40 100644
--- a/library/HTMLPurifier/AttrTransform/TargetBlank.php
+++ b/library/HTMLPurifier/AttrTransform/TargetBlank.php
@@ -26,7 +26,7 @@ class HTMLPurifier_AttrTransform_TargetBlank extends HTMLPurifier_AttrTransform
         $scheme = $url->getSchemeObj($config, $context);
 
         if ($scheme->browsable && !$url->isBenign($config, $context)) {
-            $attr['target'] = 'blank';
+            $attr['target'] = '_blank';
         }
 
         return $attr;
diff --git a/tests/HTMLPurifier/HTMLModule/TargetBlankTest.php b/tests/HTMLPurifier/HTMLModule/TargetBlankTest.php
index a757fecb..eb6208a8 100644
--- a/tests/HTMLPurifier/HTMLModule/TargetBlankTest.php
+++ b/tests/HTMLPurifier/HTMLModule/TargetBlankTest.php
@@ -11,7 +11,7 @@ class HTMLPurifier_HTMLModule_TargetBlankTest extends HTMLPurifier_HTMLModuleHar
     function testTargetBlank() {
         $this->assertResult(
             '<a href="http://google.com">a</a><a href="/local">b</a><a href="mailto:foo@example.com">c</a>',
-            '<a href="http://google.com" target="blank">a</a><a href="/local">b</a><a href="mailto:foo@example.com">c</a>'
+            '<a href="http://google.com" target="_blank">a</a><a href="/local">b</a><a href="mailto:foo@example.com">c</a>'
         );
     }