diff --git a/addon/-private/system/relationships/state/has-many.js b/addon/-private/system/relationships/state/has-many.js
index 6f8e6fa4a72..eaa76da4a07 100644
--- a/addon/-private/system/relationships/state/has-many.js
+++ b/addon/-private/system/relationships/state/has-many.js
@@ -180,6 +180,10 @@ export default class ManyRelationship extends Relationship {
   }
 
   setInitialInternalModels(internalModels) {
+    if (!internalModels) {
+      return;
+    }
+
     let args = [0, this.canonicalState.length].concat(internalModels);
     this.canonicalState.splice.apply(this.canonicalState, args);
     internalModels.forEach(internalModel => {
diff --git a/tests/unit/model/relationships/has-many-test.js b/tests/unit/model/relationships/has-many-test.js
index 9ee43d16204..d6dbc6ed962 100644
--- a/tests/unit/model/relationships/has-many-test.js
+++ b/tests/unit/model/relationships/has-many-test.js
@@ -276,6 +276,48 @@ test('hasMany does not notify when it is initially reified', function(assert) {
   });
 });
 
+test('hasMany can be initially reified with null', function(assert) {
+  assert.expect(1);
+
+  const Tag = DS.Model.extend({
+    name: DS.attr('string'),
+    people: DS.hasMany('person', { async: false })
+  });
+
+  const Person = DS.Model.extend({
+    name: DS.attr('string'),
+    tag: DS.belongsTo('tag', { async: false })
+  });
+
+  let env = setupStore({ tag: Tag, person: Person });
+  let { store } = env;
+
+  env.adapter.shouldBackgroundReloadRecord = () => false;
+
+  run(() => {
+    store.push({
+      data: {
+        type: 'tag',
+        id: 1,
+        attributes: {
+          name: 'whatever'
+        },
+        relationships: {
+          people: {
+            data: null
+          }
+        }
+      }
+    });
+  });
+
+  return run(() => {
+    let tag = store.peekRecord('tag', 1);
+
+    assert.equal(tag.get('people.length'), 0, 'relationship is correct');
+  });
+});
+
 test('hasMany tolerates reflexive self-relationships', function(assert) {
   assert.expect(1);