diff --git a/lib/src/core/interaction_output.dart b/lib/src/core/interaction_output.dart
index 5237a7c8..a484cc3b 100644
--- a/lib/src/core/interaction_output.dart
+++ b/lib/src/core/interaction_output.dart
@@ -52,11 +52,8 @@ class InteractionOutput implements scripting_api.InteractionOutput {
       return _value.internalValue;
     }
 
-    final schema = this.schema;
-    if (schema == null) {
-      // TODO: Throw NotReadableError
-      throw Exception();
-    }
+    // TODO(JKRhb): Should a NotReadableError be thrown if schema is null?
+    //              C.f. https://w3c.github.io/wot-scripting-api/#the-value-function
 
     final value = await _contentSerdes.contentToValue(
       _content,
@@ -64,8 +61,8 @@ class InteractionOutput implements scripting_api.InteractionOutput {
     );
     _dataUsed = true;
 
-    _value = (read: true, internalValue: value);
-    return value;
+    _value = (read: true, internalValue: value?.value);
+    return value?.value;
   }
 
   @override
diff --git a/lib/src/core/wot.dart b/lib/src/core/wot.dart
index 3953be85..4ffa6da1 100644
--- a/lib/src/core/wot.dart
+++ b/lib/src/core/wot.dart
@@ -117,7 +117,7 @@ class WoT implements scripting_api.WoT {
         await consumedDirectoryThing.readProperty('things');
     final rawThingDescriptions = await interactionOutput.value();
 
-    if (rawThingDescriptions is! scripting_api.DataSchemaValue<List<Object?>>) {
+    if (rawThingDescriptions is! List<Object?>) {
       throw DiscoveryException(
         'Expected an array of Thing Descriptions but received an '
         'invalid output instead.',
@@ -125,7 +125,7 @@ class WoT implements scripting_api.WoT {
     }
 
     final thingDescriptionStream = Stream.fromIterable(
-      rawThingDescriptions.value.whereType<Map<String, Object?>>(),
+      rawThingDescriptions.whereType<Map<String, Object?>>(),
     ).toThingDescriptionStream();
 
     return ThingDiscoveryProcess(thingDescriptionStream, filter);