diff --git a/lib/rdf/literal/datatypes/generic.ex b/lib/rdf/literal/datatypes/generic.ex
index be40623..0603715 100644
--- a/lib/rdf/literal/datatypes/generic.ex
+++ b/lib/rdf/literal/datatypes/generic.ex
@@ -33,7 +33,8 @@ defmodule RDF.Literal.Generic do
 
   defp normalize_datatype(nil), do: nil
   defp normalize_datatype(""), do: nil
-  defp normalize_datatype(datatype), do: IRI.new(datatype)
+  defp normalize_datatype(%IRI{} = datatype), do: to_string(datatype)
+  defp normalize_datatype(datatype), do: datatype
 
   @impl Datatype
   @spec new!(any, String.t | IRI.t | keyword) :: Literal.t
@@ -49,7 +50,7 @@ defmodule RDF.Literal.Generic do
 
   @impl Datatype
   def datatype_id(%Literal{literal: literal}), do: datatype_id(literal)
-  def datatype_id(%__MODULE__{} = literal), do: literal.datatype
+  def datatype_id(%__MODULE__{} = literal), do: RDF.iri(literal.datatype)
 
   @impl Datatype
   def value(%Literal{literal: literal}), do: value(literal)
@@ -69,7 +70,7 @@ defmodule RDF.Literal.Generic do
 
   @impl Datatype
   def valid?(%Literal{literal: %__MODULE__{} = literal}), do: valid?(literal)
-  def valid?(%__MODULE__{datatype: %IRI{}}), do: true
+  def valid?(%__MODULE__{datatype: datatype}) when is_binary(datatype), do: true
   def valid?(_), do: false
 
   @doc """
diff --git a/test/unit/datatypes/generic_test.exs b/test/unit/datatypes/generic_test.exs
index 6a70656..ba38959 100644
--- a/test/unit/datatypes/generic_test.exs
+++ b/test/unit/datatypes/generic_test.exs
@@ -12,11 +12,10 @@ defmodule RDF.Literal.GenericTest do
   describe "new" do
     test "with value and datatype" do
       Enum.each @valid, fn {input, {value, datatype}} ->
-        datatype_iri = RDF.iri(datatype)
-        assert %Literal{literal: %Generic{value: ^value, datatype: ^datatype_iri}} =
-                 Generic.new(input, datatype: datatype_iri)
-        assert %Literal{literal: %Generic{value: ^value, datatype: ^datatype_iri}} =
+        assert %Literal{literal: %Generic{value: ^value, datatype: ^datatype}} =
                  Generic.new(input, datatype: datatype)
+        assert %Literal{literal: %Generic{value: ^value, datatype: ^datatype}} =
+                 Generic.new(input, datatype: RDF.iri(datatype))
       end
     end
 
@@ -30,8 +29,7 @@ defmodule RDF.Literal.GenericTest do
 
     test "with canonicalize opts" do
       Enum.each @valid, fn {input, {value, datatype}} ->
-        datatype_iri = RDF.iri(datatype)
-        assert %Literal{literal: %Generic{value: ^value, datatype: ^datatype_iri}} =
+        assert %Literal{literal: %Generic{value: ^value, datatype: ^datatype}} =
                  Generic.new(input, datatype: datatype, canonicalize: true)
       end
     end