diff --git a/src/Datasource/InvalidPropertyInterface.php b/src/Datasource/InvalidPropertyInterface.php
index <HASH>..<HASH> 100644
--- a/src/Datasource/InvalidPropertyInterface.php
+++ b/src/Datasource/InvalidPropertyInterface.php
@@ -36,7 +36,7 @@ interface InvalidPropertyInterface
      * This value could not be patched into the entity and is simply copied into the _invalid property for debugging
      * purposes or to be able to log it away.
      *
-     * @param array $fields The values to set.
+     * @param array<string, mixed> $fields The values to set.
      * @param bool $overwrite Whether to overwrite pre-existing values for $field.
      * @return $this
      */
Fix up assoc return docblocks.