diff --git a/src/Google/Protobuf/Internal/Message.php b/src/Google/Protobuf/Internal/Message.php
index 359ba67..dc40209 100644
--- a/src/Google/Protobuf/Internal/Message.php
+++ b/src/Google/Protobuf/Internal/Message.php
@@ -1574,7 +1574,7 @@ private function existField($field)
 
         $values = $this->$getter();
 
-        if (($field->getName() === 'incrementality' || $field->getName() === 'speed' || ($field->getName() === 'delay' && $field->getNumber() === 1)) && $values !== null) {
+        if (($field->getName() === 'incrementality' || $field->getName() === 'speed' || $field->getName() === 'bearing' || ($field->getName() === 'delay' && $field->getNumber() === 1)) && $values !== null) {
             return true;
         }