diff --git a/composer.json b/composer.json
index a5e21f69..95f2610d 100644
--- a/composer.json
+++ b/composer.json
@@ -4,7 +4,7 @@
 		"mediawiki/mediawiki-codesniffer": "28.0.0",
 		"jakub-onderka/php-console-highlighter": "0.3.2",
 		"mediawiki/minus-x": "0.3.2",
-		"mediawiki/mediawiki-phan-config": "0.8.0"
+		"mediawiki/mediawiki-phan-config": "0.9.0"
 	},
 	"scripts": {
 		"fix": [
diff --git a/src/ReplaceTextJob.php b/src/ReplaceTextJob.php
index 9f4482c5..ef6f3b3a 100644
--- a/src/ReplaceTextJob.php
+++ b/src/ReplaceTextJob.php
@@ -32,7 +32,7 @@ class ReplaceTextJob extends Job {
 	 * @param Title $title
 	 * @param array|bool $params Cannot be === true
 	 */
-	function __construct( $title, $params = '' ) {
+	function __construct( $title, $params = [] ) {
 		parent::__construct( 'replaceText', $title, $params );
 	}
 
diff --git a/src/ReplaceTextSearch.php b/src/ReplaceTextSearch.php
index a729e4df..9c9acae5 100644
--- a/src/ReplaceTextSearch.php
+++ b/src/ReplaceTextSearch.php
@@ -26,8 +26,8 @@ class ReplaceTextSearch {
 	/**
 	 * @param string $search
 	 * @param array $namespaces
-	 * @param string $category
-	 * @param string $prefix
+	 * @param string|null $category
+	 * @param string|null $prefix
 	 * @param bool $use_regex
 	 * @return IResultWrapper Resulting rows
 	 */
@@ -65,7 +65,7 @@ class ReplaceTextSearch {
 	}
 
 	/**
-	 * @param string $category
+	 * @param string|null $category
 	 * @param array &$tables
 	 * @param array &$conds
 	 */
@@ -79,7 +79,7 @@ class ReplaceTextSearch {
 	}
 
 	/**
-	 * @param string $prefix
+	 * @param string|null $prefix
 	 * @param array &$conds
 	 */
 	public static function prefixCondition( $prefix, &$conds ) {
@@ -93,6 +93,7 @@ class ReplaceTextSearch {
 			$prefix = $title->getDbKey();
 		}
 		$any = $dbr->anyString();
+		// @phan-suppress-next-line PhanTypeMismatchArgumentNullable strval makes this non-null
 		$conds[] = 'page_title ' . $dbr->buildLike( $prefix, $any );
 	}
 
@@ -114,8 +115,8 @@ class ReplaceTextSearch {
 	/**
 	 * @param string $str
 	 * @param array $namespaces
-	 * @param string $category
-	 * @param string $prefix
+	 * @param string|null $category
+	 * @param string|null $prefix
 	 * @param bool $use_regex
 	 * @return IResultWrapper Resulting rows
 	 */
diff --git a/src/SpecialReplaceText.php b/src/SpecialReplaceText.php
index 8195f817..655bc95d 100644
--- a/src/SpecialReplaceText.php
+++ b/src/SpecialReplaceText.php
@@ -272,10 +272,10 @@ class SpecialReplaceText extends SpecialPage {
 		foreach ( $request->getValues() as $key => $value ) {
 			if ( $value == '1' && $key !== 'replace' && $key !== 'use_regex' ) {
 				if ( strpos( $key, 'move-' ) !== false ) {
-					$title = Title::newFromID( substr( $key, 5 ) );
+					$title = Title::newFromID( (int)substr( $key, 5 ) );
 					$replacement_params['move_page'] = true;
 				} else {
-					$title = Title::newFromID( $key );
+					$title = Title::newFromID( (int)$key );
 				}
 				if ( $title !== null ) {
 					$jobs[] = new ReplaceTextJob( $title, $replacement_params );