diff --git a/Model/ModelRegistry.php b/Model/ModelRegistry.php
index c922741..53a9641 100644
--- a/Model/ModelRegistry.php
+++ b/Model/ModelRegistry.php
@@ -40,36 +40,30 @@ final class ModelRegistry
     {
         $this->modelDescribers = $modelDescribers;
         $this->api = $api;
-        $this->alternativeNames = array_reverse($alternativeNames); // last rule wins
+        $this->alternativeNames = []; // last rule wins
 
-        foreach ($this->alternativeNames as $alternativeName => $criteria) {
-            $this->doRegister(new Model(new Type('object', false, $criteria['type']), $criteria['groups']), $alternativeName);
+        foreach (array_reverse($alternativeNames) as $alternativeName => $criteria) {
+            $this->alternativeNames[] = $model = new Model(new Type('object', false, $criteria['type']), $criteria['groups']);
+            $this->names[$model->getHash()] = $alternativeName;
+            $this->api->getDefinitions()->get($alternativeName);
         }
     }
 
     public function register(Model $model): string
-    {
-        return $this->doRegister($model);
-    }
-
-    /**
-     * Private method allowing to enforce the model name for alternative names.
-     */
-    private function doRegister(Model $model, string $name = null)
     {
         $hash = $model->getHash();
-        if (isset($this->names[$hash])) {
-            return '#/definitions/'.$this->names[$hash];
+        if (!isset($this->models[$hash])) {
+            $this->models[$hash] = $model;
+            $this->unregistered[] = $hash;
+        }
+        if (!isset($this->names[$hash])) {
+            $this->names[$hash] = $this->generateModelName($model);
         }
 
-        $this->names[$hash] = $name = ($name ?? $this->generateModelName($model));
-        $this->models[$hash] = $model;
-        $this->unregistered[] = $hash;
-
         // Reserve the name
-        $this->api->getDefinitions()->get($name);
+        $this->api->getDefinitions()->get($this->names[$hash]);
 
-        return '#/definitions/'.$name;
+        return '#/definitions/'.$this->names[$hash];
     }
 
     /**
@@ -104,6 +98,13 @@ final class ModelRegistry
 
                 $this->api->getDefinitions()->set($name, $schema);
             }
+
+            if (0 === count($this->unregistered)) {
+                foreach ($this->alternativeNames as $model) {
+                    $this->register($model);
+                }
+                $this->alternativeNames = [];
+            }
         }
     }
 
diff --git a/ModelDescriber/JMSModelDescriber.php b/ModelDescriber/JMSModelDescriber.php
index c3c33c5..613f099 100644
--- a/ModelDescriber/JMSModelDescriber.php
+++ b/ModelDescriber/JMSModelDescriber.php
@@ -81,7 +81,7 @@ class JMSModelDescriber implements ModelDescriberInterface, ModelRegistryAwareIn
             if (isset($groups[$name]) && is_array($groups[$name])) {
                 $previousGroups = $groups;
                 $groups = $model->getGroups()[$name];
-            } elseif (!isset($groups[$name]) && !empty($this->previousGroups[spl_object_hash($model)])) {
+            } elseif (!isset($groups[$name]) && !empty($this->previousGroups[$model->getHash()])) {
                 // $groups = $this->previousGroups[spl_object_hash($model)]; use this for jms/serializer 2.0
                 $groups = false === $this->propertyTypeUsesGroups($item->type) ? null : [GroupsExclusionStrategy::DEFAULT_GROUP];
             } elseif (is_array($groups)) {
@@ -171,12 +171,11 @@ class JMSModelDescriber implements ModelDescriberInterface, ModelRegistryAwareIn
                 return null;
             }
 
-            $property->setRef($this->modelRegistry->register(
-                new Model(new Type(Type::BUILTIN_TYPE_OBJECT, false, $type['name']), $groups)
-            ));
+            $model = new Model(new Type(Type::BUILTIN_TYPE_OBJECT, false, $type['name']), $groups);
+            $property->setRef($this->modelRegistry->register($model));
 
             if ($previousGroups) {
-                $this->previousGroups[spl_object_hash($model)] = $previousGroups;
+                $this->previousGroups[$model->getHash()] = $previousGroups;
             }
         }
     }
@@ -205,7 +204,7 @@ class JMSModelDescriber implements ModelDescriberInterface, ModelRegistryAwareIn
      */
     private function propertyTypeUsesGroups(array $type)
     {
-        if (!array_key_exists($type['name'], $this->propertyTypeUseGroupsCache)) {
+        if (array_key_exists($type['name'], $this->propertyTypeUseGroupsCache)) {
             return $this->propertyTypeUseGroupsCache[$type['name']];
         }