diff --git a/idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/frontend/api/fir/KtSymbolByFirBuilder.kt b/idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/frontend/api/fir/KtSymbolByFirBuilder.kt
index a08762e31fa..4e74f05be30 100644
--- a/idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/frontend/api/fir/KtSymbolByFirBuilder.kt
+++ b/idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/frontend/api/fir/KtSymbolByFirBuilder.kt
@@ -201,6 +201,7 @@ internal class KtSymbolByFirBuilder private constructor(
             is ConeClassErrorType -> KtFirErrorType(coneType, typeCheckerContext, token)
             is ConeFlexibleType -> KtFirFlexibleType(coneType, typeCheckerContext, token, this)
             is ConeIntersectionType -> KtFirIntersectionType(coneType, typeCheckerContext, token, this)
+            is ConeDefinitelyNotNullType -> buildKtType(coneType.original)
             else -> TODO(coneType::class.toString())
         }
     }