diff --git a/libraries/tools/kdoc/src/main/kotlin/org/jetbrains/kotlin/doc/model/KotlinModel.kt b/libraries/tools/kdoc/src/main/kotlin/org/jetbrains/kotlin/doc/model/KotlinModel.kt
index 7c5f0e5bffd..a12323578aa 100644
--- a/libraries/tools/kdoc/src/main/kotlin/org/jetbrains/kotlin/doc/model/KotlinModel.kt
+++ b/libraries/tools/kdoc/src/main/kotlin/org/jetbrains/kotlin/doc/model/KotlinModel.kt
@@ -1007,7 +1007,7 @@ class KType(val jetType: JetType, model: KModel, val klass: KClass?, val argumen
     override fun toString() = if (nullable) "$name?" else name
 
     val nullable: Boolean
-    get() = jetType.isNullable()
+    get() = jetType.isMarkedNullable()
 }
 
 class KClass(