diff --git a/src/Data/OpenApi/Internal/Schema.hs b/src/Data/OpenApi/Internal/Schema.hs
index 212b2a40..43e9e438 100644
--- a/src/Data/OpenApi/Internal/Schema.hs
+++ b/src/Data/OpenApi/Internal/Schema.hs
@@ -951,9 +951,11 @@ instance {-# OVERLAPPING #-} Constructor c => GToSchema (C1 c U1) where
   gdeclareNamedSchema = gdeclareNamedSumSchema
 
 -- | Single field constructor.
-instance (Selector s, GToSchema f, GToSchema (S1 s f)) => GToSchema (C1 c (S1 s f)) where
+instance (Selector s, GToSchema f, GToSchema (S1 s f), GSumToSchema (S1 s f)) => GToSchema (C1 c (S1 s f)) where
   gdeclareNamedSchema opts _ s
     | unwrapUnaryRecords opts = fieldSchema
+    | tagSingleConstructors opts = do
+        gdeclareNamedSumSchema opts (Proxy :: Proxy (S1 s f)) s
     | otherwise =
         case schema ^. items of
           Just (OpenApiItemsArray [_]) -> fieldSchema
@@ -1116,7 +1118,7 @@ instance {-# OVERLAPPABLE #-} (Constructor c, GToSchema f) => GSumToSchema (C1 c
     tell (All False)
     lift $ gsumConToSchema opts proxy
 
-instance (Constructor c, Selector s, GToSchema f) => GSumToSchema (C1 c (S1 s f)) where
+instance (Constructor c, Selector s, GToSchema f, GSumToSchema (S1 s f)) => GSumToSchema (C1 c (S1 s f)) where
   gsumToSchema opts proxy = do
     tell (All False)
     lift $ gsumConToSchema opts proxy
diff --git a/src/Data/OpenApi/SchemaOptions.hs b/src/Data/OpenApi/SchemaOptions.hs
index ed95881f..27bd5f37 100644
--- a/src/Data/OpenApi/SchemaOptions.hs
+++ b/src/Data/OpenApi/SchemaOptions.hs
@@ -24,6 +24,7 @@ data SchemaOptions = SchemaOptions
   , unwrapUnaryRecords :: Bool
     -- | Specifies how to encode constructors of a sum datatype.
   , sumEncoding :: Aeson.SumEncoding
+  , tagSingleConstructors :: Bool
   }
 
 -- | Default encoding @'SchemaOptions'@.
@@ -39,14 +40,7 @@ data SchemaOptions = SchemaOptions
 -- }
 -- @
 defaultSchemaOptions :: SchemaOptions
-defaultSchemaOptions = SchemaOptions
-  { fieldLabelModifier = id
-  , constructorTagModifier = id
-  , datatypeNameModifier = id
-  , allNullaryToStringTag = True
-  , unwrapUnaryRecords = False
-  , sumEncoding = Aeson.defaultTaggedObject
-  }
+defaultSchemaOptions = fromAesonOptions Aeson.defaultOptions
 
 -- | Convert 'Aeson.Options' to 'SchemaOptions'.
 --
@@ -56,21 +50,25 @@ defaultSchemaOptions = SchemaOptions
 -- * 'constructorTagModifier'
 -- * 'allNullaryToStringTag'
 -- * 'unwrapUnaryRecords'
+-- * 'sumEncoding'
 --
 -- Note that these fields have no effect on `SchemaOptions`:
 --
 -- * 'Aeson.omitNothingFields'
 -- * 'Aeson.tagSingleConstructors'
+-- * 'Aeson.rejectUnknownFields'
 --
 -- The rest is defined as in 'defaultSchemaOptions'.
 --
 -- @since 2.2.1
 --
 fromAesonOptions :: Aeson.Options -> SchemaOptions
-fromAesonOptions opts = defaultSchemaOptions
+fromAesonOptions opts = SchemaOptions
   { fieldLabelModifier     = Aeson.fieldLabelModifier     opts
   , constructorTagModifier = Aeson.constructorTagModifier opts
+  , datatypeNameModifier   = id
   , allNullaryToStringTag  = Aeson.allNullaryToStringTag  opts
   , unwrapUnaryRecords     = Aeson.unwrapUnaryRecords     opts
   , sumEncoding            = Aeson.sumEncoding            opts
+  , tagSingleConstructors  = Aeson.tagSingleConstructors  opts
   }