diff --git a/src/Qowaiv.Bson.MongoDB/QowaivBsonSerializationProvider.cs b/src/Qowaiv.Bson.MongoDB/QowaivBsonSerializationProvider.cs
index 60b2355..bcd4df1 100644
--- a/src/Qowaiv.Bson.MongoDB/QowaivBsonSerializationProvider.cs
+++ b/src/Qowaiv.Bson.MongoDB/QowaivBsonSerializationProvider.cs
@@ -16,7 +16,7 @@ public sealed class QowaivBsonSerializationProvider : IBsonSerializationProvider
     {
         IBsonSerializer? serializer = null;
 
-        if (TypeHelper.GetCandidateType(type) is not { } tp
+        if (GetCandidateType(type) is not { } tp
             || NotSupported.Contains(tp)
             || Serializers.TryGetValue(tp, out serializer))
         {
@@ -56,6 +56,20 @@ private static bool IsSupported(IBsonSerializer converter)
         .GetProperty(nameof(QowaivBsonSerializer<object>.TypeIsSupported), NonPublicInstance)!
         .GetValue(converter, Array.Empty<object>())!;
 
+    [Pure]
+    private static Type? GetCandidateType(Type? type)
+    {
+        return TypeHelper.NotNullable(type) is { } tp && IsSupported(tp)
+            ? tp
+            : null;
+
+        static bool IsSupported(Type type)
+            => !type.IsAbstract
+            && !type.IsGenericTypeDefinition
+            && !type.ContainsGenericParameters
+            && !type.IsGenericTypeDefinition;
+    }
+
 #pragma warning disable S3011
 
     // Reflection should not be used to increase accessibility of classes, methods, or fields
diff --git a/test/Qowaiv.Json.UnitTests/Bson.MongoDB/BSON_serialization_provider_specs.cs b/test/Qowaiv.Json.UnitTests/Bson.MongoDB/BSON_serialization_provider_specs.cs
index 9a38c59..02654ae 100644
--- a/test/Qowaiv.Json.UnitTests/Bson.MongoDB/BSON_serialization_provider_specs.cs
+++ b/test/Qowaiv.Json.UnitTests/Bson.MongoDB/BSON_serialization_provider_specs.cs
@@ -21,7 +21,7 @@ public void nullable_FromJson_string_only_SVO()
         .Should().BeOfType<QowaivBsonSerializer<SvoWithFromJsonStringOnly>>();
 
     [Test]
-    public void FromJson_string_only_SVO_class()
+    public void FromJson_SVO_class()
         => provider.GetSerializer(typeof(SvoWithFromJsonClass))
         .Should().BeOfType<QowaivBsonSerializer<SvoWithFromJsonClass>>();
 
@@ -30,21 +30,10 @@ public void Qowaiv_ID()
         => provider.GetSerializer(typeof(Id<SomeIdBehavior>))
         .Should().BeOfType<QowaivBsonSerializer<Id<SomeIdBehavior>>>();
 
-
-    [Test]
-    public void Qowaiv_ID_via_behavior()
-        => provider.GetSerializer(typeof(SomeIdBehavior))
-        .Should().BeOfType<QowaivBsonSerializer<Id<SomeIdBehavior>>>();
-
     [Test]
     public void Qowaiv_generic_SVO()
         => provider.GetSerializer(typeof(Svo<SomeSvoBehavior>))
         .Should().BeOfType<QowaivBsonSerializer<Svo<SomeSvoBehavior>>>();
-
-    [Test]
-    public void Qowaiv_generic_SVO_via_behavior()
-        => provider.GetSerializer(typeof(SomeSvoBehavior))
-        .Should().BeOfType<QowaivBsonSerializer<Svo<SomeSvoBehavior>>>();
 }
 
 public class Gets_null
@@ -68,7 +57,7 @@ public void DTO()
         => provider.GetSerializer(typeof(DtoClass)).Should().BeNull();
 }
 
-class Cashes_for_performance_reasons
+class Caches_for_performance_reasons
 {
     [Test]
     public void serializers_already_requested()