diff --git a/Gemfile.lock b/Gemfile.lock
index 9b14156..fd5a943 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -3,7 +3,7 @@ PATH
   specs:
     evva (0.9.0)
       colorize (~> 1.0)
-      csv (>= 3.0)
+      csv (~> 3.0)
       safe_yaml (~> 1.0)
 
 GEM
diff --git a/changelog.md b/changelog.md
index 34e2976..75d53a2 100644
--- a/changelog.md
+++ b/changelog.md
@@ -2,6 +2,8 @@
 
 ## [Unreleased]
 
+- Support optional people properties in Kotlin: `innerValue` is now `Any?` and optional special properties use `value?.key`
+
 ## [0.9.0] - 2026-09-04
 
 - Add `Platform` column support in the events sheet and `filter_by_platforms` configuration to filter generated events by platform
diff --git a/lib/evva/kotlin_generator.rb b/lib/evva/kotlin_generator.rb
index cfbaab3..aec8e25 100644
--- a/lib/evva/kotlin_generator.rb
+++ b/lib/evva/kotlin_generator.rb
@@ -84,11 +84,21 @@ def people_properties(people_bundle, file_name, enums_file_name, destinations_fi
 
         properties = people_bundle.map do |property|
           type = native_type(property.type)
+          value_fetcher = "value"
+
+          if special_property?(type)
+            if type.end_with?("?")
+              # optional value, we need ? to access a parameter
+              value_fetcher += "?"
+            end
+            value_fetcher += ".key"
+          end
+
           {
             class_name: camelize(property.property_name),
             property_name: constantize(property.property_name),
             type: type,
-            is_special_property: special_property?(property.type),
+            value_fetcher: value_fetcher,
             destinations: property.destinations.map { |p| constantize(p) },
           }
         end
diff --git a/lib/evva/templates/kotlin/people_properties.kt b/lib/evva/templates/kotlin/people_properties.kt
index 4d3dd85..a47a8a2 100644
--- a/lib/evva/templates/kotlin/people_properties.kt
+++ b/lib/evva/templates/kotlin/people_properties.kt
@@ -1,6 +1,6 @@
 sealed class <%= class_name %>(
 	property: <%= enums_class_name %>,
-	val innerValue: Any,
+	val innerValue: Any?,
 	val destinations: Array<<%= destinations_class_name %>> = emptyArray(),
 ) {
 	val name = property.key
@@ -10,7 +10,7 @@ sealed class <%= class_name %>(
 		val value: <%= property[:type] %>,
 	) : <%= class_name %>(
 		property = <%= enums_class_name %>.<%= property[:property_name] %>,
-		innerValue = value<% if property[:is_special_property] %>.key<% end %>,
+		innerValue = <%= property[:value_fetcher] %>,
 		<%- if property[:destinations].count > 0 -%>
 		destinations = arrayOf(
 			<%- property[:destinations].each_with_index do |d, index| -%>
diff --git a/spec/lib/evva/kotlin_generator_spec.rb b/spec/lib/evva/kotlin_generator_spec.rb
index 2ff6dad..a6f6974 100644
--- a/spec/lib/evva/kotlin_generator_spec.rb
+++ b/spec/lib/evva/kotlin_generator_spec.rb
@@ -156,9 +156,10 @@
   describe "#people_properties" do
     subject { generator.people_properties(people_bundle, "AnalyticsProperty", "AnalyticsProperties", "AnalyticsDestinations") }
     let(:people_bundle) { [
-      Evva::AnalyticsProperty.new("rounds_with_wear", "String", []),
+      Evva::AnalyticsProperty.new("rounds_with_wear", "String?", []),
       Evva::AnalyticsProperty.new("last_active_at", "Date", []),
-      Evva::AnalyticsProperty.new("wear_platform", "WearableAppPlatform", ["firebase", "custom destination"]),
+      Evva::AnalyticsProperty.new("upgrade_source", "PremiumFrom", []),
+      Evva::AnalyticsProperty.new("wear_platform", "WearableAppPlatform?", ["firebase", "custom destination"]),
     ] }
     let(:expected) {
 <<-Kotlin
@@ -170,13 +171,13 @@
 
 sealed class AnalyticsProperty(
     property: AnalyticsProperties,
-    val innerValue: Any,
+    val innerValue: Any?,
     val destinations: Array<AnalyticsDestinations> = emptyArray(),
 ) {
     val name = property.key
 
     data class RoundsWithWear(
-        val value: String,
+        val value: String?,
     ) : AnalyticsProperty(
         property = AnalyticsProperties.ROUNDS_WITH_WEAR,
         innerValue = value,
@@ -189,11 +190,18 @@
         innerValue = value,
     )
 
+    data class UpgradeSource(
+        val value: PremiumFrom,
+    ) : AnalyticsProperty(
+        property = AnalyticsProperties.UPGRADE_SOURCE,
+        innerValue = value.key,
+    )
+
     data class WearPlatform(
-        val value: WearableAppPlatform,
+        val value: WearableAppPlatform?,
     ) : AnalyticsProperty(
         property = AnalyticsProperties.WEAR_PLATFORM,
-        innerValue = value.key,
+        innerValue = value?.key,
         destinations = arrayOf(
             AnalyticsDestinations.FIREBASE,
             AnalyticsDestinations.CUSTOM_DESTINATION,