src/Normalizer/Value/RelationshipNormalizerValue.php | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/src/Normalizer/Value/RelationshipNormalizerValue.php b/src/Normalizer/Value/RelationshipNormalizerValue.php
index df0d653..2cad6e9 100644
--- a/src/Normalizer/Value/RelationshipNormalizerValue.php
+++ b/src/Normalizer/Value/RelationshipNormalizerValue.php
@@ -104,14 +104,29 @@ class RelationshipNormalizerValue extends FieldNormalizerValue {
 
     $unique_resource_identifier_objects = array_reduce($resource_identifier_objects, function ($carry, $resource_identifier_object) {
       $id = $resource_identifier_object['id'];
+      $has_meta = isset($resource_identifier_object['meta']);
+
       if (!isset($carry[$id])) {
         $carry[$id] = $resource_identifier_object;
+        if ($has_meta) {
+          // All resource identifier objects' metas need to be nested.
+          unset($carry[$id]['meta']);
+        }
       }
       else {
-        if (!isset($carry[$id]['meta'])) {
+        // Increment arity.
+        if (!isset($carry[$id]['meta']['arity'])) {
           $carry[$id]['meta']['arity'] = 1;
         }
         $carry[$id]['meta']['arity']++;
+
+        // Nest all resource identifier objects' metas under a shared key.
+        if ($has_meta) {
+          if (!isset($carry[$id]['meta']['metas'])) {
+            $carry[$id]['meta']['metas'] = [];
+          }
+          $carry[$id]['meta']['metas'][] = $resource_identifier_object['meta'];
+        }
       }
       return $carry;
     }, []);