2 files changed, 14 insertions, 4 deletions
diff --git a/core/src/main/kotlin/model/Documentable.kt b/core/src/main/kotlin/model/Documentable.kt
index adc51cfc..c7b2290e 100644
--- a/core/src/main/kotlin/model/Documentable.kt
+++ b/core/src/main/kotlin/model/Documentable.kt
@@ -376,8 +376,9 @@ data class DTypeAlias(
     override val expectPresentInSet: DokkaSourceSet?,
     override val sourceSets: Set<DokkaSourceSet>,
     override val generics: List<DTypeParameter>,
+    override val sources: SourceSetDependent<DocumentableSource>,
     override val extra: PropertyContainer<DTypeAlias> = PropertyContainer.empty()
-) : Documentable(), WithType, WithVisibility, WithExtraProperties<DTypeAlias>, WithGenerics {
+) : Documentable(), WithType, WithVisibility, WithExtraProperties<DTypeAlias>, WithGenerics, WithSources {
     override val children: List<Nothing>
         get() = emptyList()
 
diff --git a/core/src/main/kotlin/model/additionalExtras.kt b/core/src/main/kotlin/model/additionalExtras.kt
index 9b98448e..1f6f6d27 100644
--- a/core/src/main/kotlin/model/additionalExtras.kt
+++ b/core/src/main/kotlin/model/additionalExtras.kt
@@ -104,13 +104,22 @@ object PrimaryConstructorExtra : ExtraProperty<DFunction>, ExtraProperty.Key<DFu
     override val key: ExtraProperty.Key<DFunction, *> = this
 }
 
-data class ActualTypealias(val underlyingType: SourceSetDependent<Bound>) : ExtraProperty<DClasslike> {
+data class ActualTypealias(
+    val typeAlias: DTypeAlias
+) : ExtraProperty<DClasslike> {
+
+    @Suppress("unused")
+    @Deprecated(message = "It can be removed soon. Use [typeAlias.underlyingType]", ReplaceWith("this.typeAlias.underlyingType"))
+    val underlyingType: SourceSetDependent<Bound>
+        get() = typeAlias.underlyingType
+
     companion object : ExtraProperty.Key<DClasslike, ActualTypealias> {
         override fun mergeStrategyFor(
             left: ActualTypealias,
             right: ActualTypealias
-        ) =
-            MergeStrategy.Replace(ActualTypealias(left.underlyingType + right.underlyingType))
+        ) = MergeStrategy.Fail {
+            throw IllegalStateException("Adding [ActualTypealias] should be after merging all documentables")
+        }
     }
 
     override val key: ExtraProperty.Key<DClasslike, ActualTypealias> = ActualTypealias