diff --git a/Gemfile.lock b/Gemfile.lock
index 5d9184a24..943e88b05 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -249,7 +249,7 @@ GEM
     minitest (5.22.3)
     mongo (2.19.3)
       bson (>= 4.14.1, < 5.0.0)
-    mongoid (8.1.4)
+    mongoid (8.1.5)
       activemodel (>= 5.1, < 7.2, != 7.0.0)
       concurrent-ruby (>= 1.0.5, < 2.0)
       mongo (>= 2.18.0, < 3.0.0)
diff --git a/spec/models/travel_advice_edition_spec.rb b/spec/models/travel_advice_edition_spec.rb
index bba7c55a0..562ae771a 100644
--- a/spec/models/travel_advice_edition_spec.rb
+++ b/spec/models/travel_advice_edition_spec.rb
@@ -571,9 +571,11 @@
   context "parts" do
     it "should merge part validation errors with parent document's errors" do
       edition = create(:travel_advice_edition)
-      edition.parts.build(_id: "54c10d4d759b743528000010", order: "1", title: "", slug: "overview")
-      edition.parts.build(_id: "54c10d4d759b743528000011", order: "2", title: "Prepare for your appointment", slug: "")
-      edition.parts.build(_id: "54c10d4d759b743528000012", order: "3", title: "Valid", slug: "valid")
+      edition.parts = [
+        Part.new(_id: "54c10d4d759b743528000010", order: "1", title: "", slug: "overview"),
+        Part.new(_id: "54c10d4d759b743528000011", order: "2", title: "Prepare for your appointment", slug: ""),
+        Part.new(_id: "54c10d4d759b743528000012", order: "3", title: "Valid", slug: "valid"),
+      ]
 
       expect(edition).not_to be_valid