diff --git a/src/Support/Exporter.php b/src/Support/Exporter.php
index ea02ce61..d653fc02 100644
--- a/src/Support/Exporter.php
+++ b/src/Support/Exporter.php
@@ -64,6 +64,8 @@ final class Exporter
                 continue;
             }
 
+            assert(is_array($data));
+
             $result[] = $context->contains($data[$key]) !== false
                 ? '*RECURSION*'
                 : sprintf('[%s]', $this->shortenedRecursiveExport($data[$key], $context));