diff --git a/visionforge-gdml/src/jvmTest/kotlin/hep/dataforge/vision/gdml/TestConvertor.kt b/visionforge-gdml/src/jvmTest/kotlin/hep/dataforge/vision/gdml/TestConvertor.kt
index cf9fb7b4..2dac5a76 100644
--- a/visionforge-gdml/src/jvmTest/kotlin/hep/dataforge/vision/gdml/TestConvertor.kt
+++ b/visionforge-gdml/src/jvmTest/kotlin/hep/dataforge/vision/gdml/TestConvertor.kt
@@ -1,9 +1,9 @@
 package hep.dataforge.vision.gdml
 
 import hep.dataforge.vision.solid.encodeToString
+import kscience.gdml.GDML
 import nl.adaptivity.xmlutil.StAXReader
 import org.junit.jupiter.api.Test
-import kscience.gdml.GDML
 
 class TestConvertor {
 
diff --git a/visionforge-solid/src/commonMain/kotlin/hep/dataforge/vision/solid/SolidManager.kt b/visionforge-solid/src/commonMain/kotlin/hep/dataforge/vision/solid/SolidManager.kt
index 5cc3948c..676ee9ba 100644
--- a/visionforge-solid/src/commonMain/kotlin/hep/dataforge/vision/solid/SolidManager.kt
+++ b/visionforge-solid/src/commonMain/kotlin/hep/dataforge/vision/solid/SolidManager.kt
@@ -12,9 +12,7 @@ import hep.dataforge.vision.Vision
 import hep.dataforge.vision.VisionForm
 import hep.dataforge.vision.VisionManager
 import hep.dataforge.vision.VisionManager.Companion.VISION_SERIAL_MODULE_TARGET
-import kotlinx.serialization.DeserializationStrategy
-import kotlinx.serialization.ExperimentalSerializationApi
-import kotlinx.serialization.KSerializer
+import kotlinx.serialization.*
 import kotlinx.serialization.json.Json
 import kotlinx.serialization.modules.*
 import kotlin.reflect.KClass
@@ -114,6 +112,19 @@ public class SolidManager(meta: Meta) : AbstractPlugin(meta) {
                 subclass(SolidLabel.serializer())
                 subclass(Sphere.serializer())
             }
+
+            polymorphic(Solid::class) {
+                subclass(SolidGroup.serializer())
+                subclass(Proxy.serializer())
+                subclass(Composite.serializer())
+                subclass(Tube.serializer())
+                subclass(Box.serializer())
+                subclass(Convex.serializer())
+                subclass(Extruded.serializer())
+                subclass(PolyLine.serializer())
+                subclass(SolidLabel.serializer())
+                subclass(Sphere.serializer())
+            }
         }
 
         val jsonForSolids = Json {