diff --git a/Modules/ContentKit/Examples/ContentKitExample/Sources/ActivityDetailsView.swift b/Modules/ContentKit/Examples/ContentKitExample/Sources/ActivityDetailsView.swift
index 8519802a2f..5d3cd64de3 100644
--- a/Modules/ContentKit/Examples/ContentKitExample/Sources/ActivityDetailsView.swift
+++ b/Modules/ContentKit/Examples/ContentKitExample/Sources/ActivityDetailsView.swift
@@ -131,7 +131,7 @@ struct ActivityDetailsView: View {
             Section("Details (in: \(l10n.language.identifier))") {
                 Text(self.activity.details.title)
                     .font(.title)
-                Text(self.activity.details.subtitle)
+                Text(self.activity.details.subtitle ?? "no subtitle")
                     .font(.title2)
                 Markdown(self.activity.details.description)
                     .markdownTheme(.gitHub)
diff --git a/Modules/ContentKit/Resources/Content/activities/examples/sample_6-2FE0B8BDD1B0497F87B32A390119DB98.activity.yml b/Modules/ContentKit/Resources/Content/activities/examples/sample_6-2FE0B8BDD1B0497F87B32A390119DB98.activity.yml
index 0d288455d8..338b8e9a57 100644
--- a/Modules/ContentKit/Resources/Content/activities/examples/sample_6-2FE0B8BDD1B0497F87B32A390119DB98.activity.yml
+++ b/Modules/ContentKit/Resources/Content/activities/examples/sample_6-2FE0B8BDD1B0497F87B32A390119DB98.activity.yml
@@ -43,7 +43,7 @@ l10n:
       icon: sample_6
 
       title: Activité d'exemple 6
-      subtitle: pour le développement
+      subtitle: null
 
       short_description: >
         Nunc Corinthiaci anilem, rerum primo et ambos fata? Et Drya aliis abest, *adeunt
@@ -74,7 +74,7 @@ l10n:
       icon: sample_6
 
       title: Sample activity 6
-      subtitle: for development
+      subtitle: null
 
       short_description: >
         Nunc Corinthiaci anilem, rerum primo et ambos fata? Et Drya aliis abest, *adeunt
diff --git a/Modules/ContentKit/Sources/Activity/Activity.swift b/Modules/ContentKit/Sources/Activity/Activity.swift
index d43b74804e..a330bd15e2 100644
--- a/Modules/ContentKit/Sources/Activity/Activity.swift
+++ b/Modules/ContentKit/Sources/Activity/Activity.swift
@@ -132,7 +132,7 @@ public extension Activity {
 
         public let icon: String
         public let title: String
-        public let subtitle: String
+        public let subtitle: String?
         public let shortDescription: String
         public let description: String
         public let instructions: String
diff --git a/Modules/GameEngineKit/Sources/Views/Activity/ActivityDetailsView.swift b/Modules/GameEngineKit/Sources/Views/Activity/ActivityDetailsView.swift
index 3c9858e32d..9ad9929dc1 100644
--- a/Modules/GameEngineKit/Sources/Views/Activity/ActivityDetailsView.swift
+++ b/Modules/GameEngineKit/Sources/Views/Activity/ActivityDetailsView.swift
@@ -33,9 +33,11 @@ public struct ActivityDetailsView: View {
                                 .font(.largeTitle)
                                 .bold()
 
-                            Text(self.activity.details.subtitle)
-                                .font(.title2)
-                                .foregroundColor(.secondary)
+                            if let subtitle = self.activity.details.subtitle {
+                                Text(subtitle)
+                                    .font(.title2)
+                                    .foregroundColor(.secondary)
+                            }
 
                             Text(self.activity.details.shortDescription)
                                 .font(.subheadline)
diff --git a/Specs/jtd/activity.jtd.json b/Specs/jtd/activity.jtd.json
index 11ec3518e3..58261e4c7e 100644
--- a/Specs/jtd/activity.jtd.json
+++ b/Specs/jtd/activity.jtd.json
@@ -99,7 +99,8 @@
                     "type": "string"
                 },
                 "subtitle": {
-                    "type": "string"
+                    "type": "string",
+                    "nullable": true
                 },
                 "short_description": {
                     "type": "string"