diff --git a/includes/Rest/ConditionalHeaderUtil.php b/includes/Rest/ConditionalHeaderUtil.php
index 355e48dedd8..0a39f06678c 100644
--- a/includes/Rest/ConditionalHeaderUtil.php
+++ b/includes/Rest/ConditionalHeaderUtil.php
@@ -143,11 +143,14 @@ class ConditionalHeaderUtil {
 	/**
 	 * The strong comparison function
 	 *
-	 * @param array $tag1 Parsed tag info array
-	 * @param array $tag2 Parsed tag info array
+	 * @param array|null $tag1 Parsed tag info array
+	 * @param array|null $tag2 Parsed tag info array
 	 * @return bool
 	 */
 	private function strongCompare( $tag1, $tag2 ) {
+		if ( $tag1 === null || $tag2 === null ) {
+			return false;
+		}
 		return !$tag1['weak'] && !$tag2['weak'] && $tag1['contents'] === $tag2['contents'];
 	}
 }
diff --git a/includes/media/WebPHandler.php b/includes/media/WebPHandler.php
index 0613fc27788..1a42da87c18 100644
--- a/includes/media/WebPHandler.php
+++ b/includes/media/WebPHandler.php
@@ -188,9 +188,9 @@ class WebPHandler extends BitmapHandler {
 		// Bytes 0-3 are 'VP8L'
 		// Bytes 4-7 are chunk stream size
 		// Byte 8 is 0x2F called the signature
-		if ( $header{8} != "\x2F" ) {
+		if ( $header[8] != "\x2F" ) {
 			wfDebugLog( 'WebP', __METHOD__ . ': Invalid signature: ' .
-				bin2hex( $header{8} ) . "\n" );
+				bin2hex( $header[8] ) . "\n" );
 			return [];
 		}
 		// Bytes 9-12 contain the image size
diff --git a/tests/phpunit/unit/includes/FactoryArgTestTrait.php b/tests/phpunit/unit/includes/FactoryArgTestTrait.php
index f7035b4d23e..d9f56e1aa21 100644
--- a/tests/phpunit/unit/includes/FactoryArgTestTrait.php
+++ b/tests/phpunit/unit/includes/FactoryArgTestTrait.php
@@ -91,7 +91,13 @@ trait FactoryArgTestTrait {
 
 		$pos = $param->getPosition();
 
-		$type = (string)$param->getType();
+		$type = $param->getType();
+		if ( !$type ) {
+			// Optimistically assume a string is okay
+			return "some unlikely string $pos";
+		}
+
+		$type = $type->getName();
 
 		if ( $type === 'array' ) {
 			return [ "some unlikely string $pos" ];
@@ -101,11 +107,6 @@ trait FactoryArgTestTrait {
 			return $this->createMock( $type );
 		}
 
-		if ( $type === '' ) {
-			// Optimistically assume a string is okay
-			return "some unlikely string $pos";
-		}
-
 		$this->fail( "Unrecognized parameter type $type" );
 	}