diff --git a/src/Annotator/EntityAnnotator.php b/src/Annotator/EntityAnnotator.php
index <HASH>..<HASH> 100644
--- a/src/Annotator/EntityAnnotator.php
+++ b/src/Annotator/EntityAnnotator.php
@@ -146,6 +146,9 @@ class EntityAnnotator extends AbstractAnnotator {
 		if ($association->type() === Association::MANY_TO_ONE) {
 			/** @var string $field */
 			$field = $association->getForeignKey();
+			if (is_array($field)) {
+				return false;
+			}
 			if (!isset($schema[$field]['null'])) {
 				return false;
 			}
Fixing if getForeignKey() is an array

If getForeignKey is an array return false since the field cannot be nullable.