diff --git a/extension.json b/extension.json
index 47471412..8c26fd2a 100644
--- a/extension.json
+++ b/extension.json
@@ -27,7 +27,7 @@
 		"spamblacklist": "spamblacklistlog"
 	},
 	"LogActionsHandlers": {
-		"spamblacklist/*": "SpamBlacklistLogFormatter"
+		"spamblacklist/*": "MediaWiki\\Extension\\SpamBlacklist\\SpamBlacklistLogFormatter"
 	},
 	"GrantPermissions": {
 		"viewrestrictedlogs": {
@@ -35,7 +35,7 @@
 		}
 	},
 	"APIModules": {
-		"spamblacklist": "ApiSpamBlacklist"
+		"spamblacklist": "MediaWiki\\Extension\\SpamBlacklist\\ApiSpamBlacklist"
 	},
 	"MessagesDirs": {
 		"SpamBlackList": [
@@ -44,14 +44,11 @@
 		]
 	},
 	"AutoloadClasses": {
-		"ApiSpamBlacklist": "includes/ApiSpamBlacklist.php",
 		"BaseBlacklist": "includes/BaseBlacklist.php",
-		"EmailBlacklist": "includes/EmailBlacklist.php",
-		"SpamBlacklistHooks": "includes/SpamBlacklistHooks.php",
-		"SpamBlacklist": "includes/SpamBlacklist.php",
-		"SpamBlacklistLogFormatter": "includes/SpamBlacklistLogFormatter.php",
-		"SpamRegexBatch": "includes/SpamRegexBatch.php",
-		"SpamBlacklistPreAuthenticationProvider": "includes/SpamBlacklistPreAuthenticationProvider.php"
+		"MediaWiki\\Extension\\SpamBlacklist\\BaseBlacklist": "includes/BaseBlacklist.php"
+	},
+	"AutoloadNamespaces": {
+		"MediaWiki\\Extension\\SpamBlacklist\\": "includes/"
 	},
 	"ResourceModules": {
 		"ext.spamBlacklist.visualEditor": {
@@ -83,7 +80,7 @@
 	},
 	"HookHandlers": {
 		"SpamBlacklistHookHandler": {
-			"class": "SpamBlacklistHooks"
+			"class": "MediaWiki\\Extension\\SpamBlacklist\\Hooks"
 		}
 	},
 	"config": {
@@ -104,7 +101,7 @@
 	"AuthManagerAutoConfig": {
 		"preauth": {
 			"SpamBlacklistPreAuthenticationProvider": {
-				"class": "SpamBlacklistPreAuthenticationProvider"
+				"class": "MediaWiki\\Extension\\SpamBlacklist\\SpamBlacklistPreAuthenticationProvider"
 			}
 		}
 	},
diff --git a/includes/ApiSpamBlacklist.php b/includes/ApiSpamBlacklist.php
index 06f9263d..f89fda5b 100644
--- a/includes/ApiSpamBlacklist.php
+++ b/includes/ApiSpamBlacklist.php
@@ -22,6 +22,10 @@
  * http://www.gnu.org/copyleft/gpl.html
  */
 
+namespace MediaWiki\Extension\SpamBlacklist;
+
+use ApiBase;
+use ApiResult;
 use Wikimedia\ParamValidator\ParamValidator;
 
 /**
@@ -44,7 +48,7 @@ class ApiSpamBlacklist extends ApiBase {
 		if ( $matches !== false ) {
 			// this url is blacklisted.
 			$res->addValue( 'spamblacklist', 'result', 'blacklisted' );
-			$res->setIndexedTagName( $matches, 'match' );
+			ApiResult::setIndexedTagName( $matches, 'match' );
 			$res->addValue( 'spamblacklist', 'matches', $matches );
 		} else {
 			// not blacklisted
diff --git a/includes/BaseBlacklist.php b/includes/BaseBlacklist.php
index b0f07dc3..4fa986d7 100644
--- a/includes/BaseBlacklist.php
+++ b/includes/BaseBlacklist.php
@@ -1,7 +1,14 @@
 <?php
 
+namespace MediaWiki\Extension\SpamBlacklist;
+
+use Exception;
 use MediaWiki\MediaWikiServices;
 use MediaWiki\Revision\SlotRecord;
+use ObjectCache;
+use TextContent;
+use Title;
+use User;
 
 /**
  * Base class for different kinds of blacklists
@@ -44,8 +51,8 @@ abstract class BaseBlacklist {
 	 * @var array
 	 */
 	private static $blacklistTypes = [
-		'spam' => 'SpamBlacklist',
-		'email' => 'EmailBlacklist',
+		'spam' => SpamBlacklist::class,
+		'email' => EmailBlacklist::class,
 	];
 
 	/**
@@ -446,3 +453,5 @@ abstract class BaseBlacklist {
 		// subclass this
 	}
 }
+
+class_alias( BaseBlacklist::class, 'BaseBlacklist' );
diff --git a/includes/EmailBlacklist.php b/includes/EmailBlacklist.php
index 789a89b3..eedbd53f 100644
--- a/includes/EmailBlacklist.php
+++ b/includes/EmailBlacklist.php
@@ -1,5 +1,10 @@
 <?php
 
+namespace MediaWiki\Extension\SpamBlacklist;
+
+use LogicException;
+use Title;
+use User;
 use Wikimedia\AtEase\AtEase;
 
 /**
diff --git a/includes/SpamBlacklistHooks.php b/includes/Hooks.php
similarity index 90%
rename from includes/SpamBlacklistHooks.php
rename to includes/Hooks.php
index 81c6de59..826b9d69 100644
--- a/includes/SpamBlacklistHooks.php
+++ b/includes/Hooks.php
@@ -1,21 +1,44 @@
 <?php
 
+namespace MediaWiki\Extension\SpamBlacklist;
+
+use ApiMessage;
+use Content;
+use ContentHandler;
+use EditPage;
+use Html;
+use IContextSource;
+use LogicException;
+use MediaWiki\Hook\EditFilterHook;
+use MediaWiki\Hook\EditFilterMergedContentHook;
+use MediaWiki\Hook\UploadVerifyUploadHook;
 use MediaWiki\MediaWikiServices;
 use MediaWiki\Revision\RevisionRecord;
 use MediaWiki\Storage\EditResult;
+use MediaWiki\Storage\Hook\PageSaveCompleteHook;
+use MediaWiki\Storage\Hook\ParserOutputStashForEditHook;
+use MediaWiki\User\Hook\UserCanSendEmailHook;
 use MediaWiki\User\UserIdentity;
+use Message;
+use MessageSpecifier;
+use ParserOptions;
+use ParserOutput;
+use Status;
+use UploadBase;
+use User;
 use Wikimedia\Assert\PreconditionException;
+use WikiPage;
 
 /**
  * Hooks for the spam blacklist extension
  */
-class SpamBlacklistHooks implements
-	\MediaWiki\Hook\EditFilterHook,
-	\MediaWiki\Hook\EditFilterMergedContentHook,
-	\MediaWiki\Hook\UploadVerifyUploadHook,
-	\MediaWiki\Storage\Hook\PageSaveCompleteHook,
-	\MediaWiki\Storage\Hook\ParserOutputStashForEditHook,
-	\MediaWiki\User\Hook\UserCanSendEmailHook
+class Hooks implements
+	EditFilterHook,
+	EditFilterMergedContentHook,
+	UploadVerifyUploadHook,
+	PageSaveCompleteHook,
+	ParserOutputStashForEditHook,
+	UserCanSendEmailHook
 {
 
 	/**
diff --git a/includes/SpamBlacklist.php b/includes/SpamBlacklist.php
index 2758530d..28add860 100644
--- a/includes/SpamBlacklist.php
+++ b/includes/SpamBlacklist.php
@@ -1,7 +1,16 @@
 <?php
 
-use MediaWiki\CheckUser\Hooks;
+namespace MediaWiki\Extension\SpamBlacklist;
+
+use ExtensionRegistry;
+use LogPage;
+use ManualLogEntry;
+use MediaWiki\CheckUser\Hooks as CUHooks;
 use MediaWiki\MediaWikiServices;
+use ObjectCache;
+use RequestContext;
+use Title;
+use User;
 use Wikimedia\AtEase\AtEase;
 use Wikimedia\Rdbms\Database;
 
@@ -246,7 +255,7 @@ class SpamBlacklist extends BaseBlacklist {
 				// (which is the default)
 				if ( ExtensionRegistry::getInstance()->isLoaded( 'CheckUser' ) ) {
 					$rc = $logEntry->getRecentChange( $logid );
-					Hooks::updateCheckUserData( $rc );
+					CUHooks::updateCheckUserData( $rc );
 				}
 			} else {
 				// If the log is unrestricted, publish normally to RC,
diff --git a/includes/SpamBlacklistLogFormatter.php b/includes/SpamBlacklistLogFormatter.php
index d158277a..78cb5376 100644
--- a/includes/SpamBlacklistLogFormatter.php
+++ b/includes/SpamBlacklistLogFormatter.php
@@ -1,5 +1,10 @@
 <?php
 
+namespace MediaWiki\Extension\SpamBlacklist;
+
+use LogFormatter;
+use Message;
+
 class SpamBlacklistLogFormatter extends LogFormatter {
 	/**
 	 * @return array
diff --git a/includes/SpamBlacklistPreAuthenticationProvider.php b/includes/SpamBlacklistPreAuthenticationProvider.php
index ed87203d..4a601c6f 100644
--- a/includes/SpamBlacklistPreAuthenticationProvider.php
+++ b/includes/SpamBlacklistPreAuthenticationProvider.php
@@ -1,6 +1,9 @@
 <?php
 
+namespace MediaWiki\Extension\SpamBlacklist;
+
 use MediaWiki\Auth\AbstractPreAuthenticationProvider;
+use StatusValue;
 
 class SpamBlacklistPreAuthenticationProvider extends AbstractPreAuthenticationProvider {
 	public function testForAccountCreation( $user, $creator, array $reqs ) {
diff --git a/includes/SpamRegexBatch.php b/includes/SpamRegexBatch.php
index 8a53431d..6151a7a5 100644
--- a/includes/SpamRegexBatch.php
+++ b/includes/SpamRegexBatch.php
@@ -1,5 +1,7 @@
 <?php
 
+namespace MediaWiki\Extension\SpamBlacklist;
+
 use Wikimedia\AtEase\AtEase;
 
 /**
@@ -84,7 +86,9 @@ class SpamRegexBatch {
 		return array_filter(
 			array_map( 'trim',
 				preg_replace( '/#.*$/', '',
-					$lines ) ) );
+					$lines )
+			)
+		);
 	}
 
 	/**
diff --git a/maintenance/cleanup.php b/maintenance/cleanup.php
index ee955b4d..e38e08ee 100644
--- a/maintenance/cleanup.php
+++ b/maintenance/cleanup.php
@@ -6,6 +6,7 @@
  * If all revisions contain spam, blanks the page
  */
 
+use MediaWiki\Extension\SpamBlacklist\BaseBlacklist;
 use MediaWiki\MediaWikiServices;
 use MediaWiki\Revision\RevisionLookup;
 use MediaWiki\Revision\RevisionRecord;
diff --git a/tests/phpunit/BaseBlacklistTest.php b/tests/phpunit/BaseBlacklistTest.php
index fda25611..4fe32eb3 100644
--- a/tests/phpunit/BaseBlacklistTest.php
+++ b/tests/phpunit/BaseBlacklistTest.php
@@ -19,8 +19,10 @@
  * @file
  */
 
+use MediaWiki\Extension\SpamBlacklist\BaseBlacklist;
+
 /**
- * @covers BaseBlacklist
+ * @covers \MediaWiki\Extension\SpamBlacklist\BaseBlacklist
  */
 class BaseBlacklistTest extends MediaWikiIntegrationTestCase {
 
diff --git a/tests/phpunit/SpamBlacklistTest.php b/tests/phpunit/SpamBlacklistTest.php
index 41f800ec..bb9fbe8c 100644
--- a/tests/phpunit/SpamBlacklistTest.php
+++ b/tests/phpunit/SpamBlacklistTest.php
@@ -1,11 +1,13 @@
 <?php
 
+use MediaWiki\Extension\SpamBlacklist\BaseBlacklist;
+use MediaWiki\Extension\SpamBlacklist\SpamBlacklist;
 use MediaWiki\MediaWikiServices;
 
 /**
  * @group SpamBlacklist
  * @group Database
- * @covers SpamBlacklist
+ * @covers \MediaWiki\Extension\SpamBlacklist\SpamBlacklist
  */
 class SpamBlacklistTest extends MediaWikiIntegrationTestCase {
 	/**
@@ -142,7 +144,7 @@ class SpamBlacklistTest extends MediaWikiIntegrationTestCase {
 
 		// That only works if the spam blacklist is really reset
 		$instance = BaseBlacklist::getInstance( 'spam' );
-		$reflProp = new \ReflectionProperty( $instance, 'regexes' );
+		$reflProp = new ReflectionProperty( $instance, 'regexes' );
 		$reflProp->setAccessible( true );
 		$reflProp->setValue( $instance, false );
 	}