diff --git a/lib/rdf/namespace.ex b/lib/rdf/namespace/namespace.ex
similarity index 100%
rename from lib/rdf/namespace.ex
rename to lib/rdf/namespace/namespace.ex
diff --git a/lib/rdf/vocabulary/namespace/case_validation.ex b/lib/rdf/vocabulary/namespace/case_validation.ex
index 4d78076..a3f9387 100644
--- a/lib/rdf/vocabulary/namespace/case_validation.ex
+++ b/lib/rdf/vocabulary/namespace/case_validation.ex
@@ -2,7 +2,7 @@ defmodule RDF.Vocabulary.Namespace.CaseValidation do
   import RDF.Vocabulary, only: [term_to_iri: 2]
   import RDF.Utils, only: [downcase?: 1]
 
-  alias RDF.Utils.ResourceClassifier
+  alias RDF.Vocabulary.ResourceClassifier
 
   def validate_case!(terms_and_ignored, nil, _, _, _), do: terms_and_ignored
 
diff --git a/lib/rdf/vocabulary_namespace.ex b/lib/rdf/vocabulary/namespace/vocabulary_namespace.ex
similarity index 100%
rename from lib/rdf/vocabulary_namespace.ex
rename to lib/rdf/vocabulary/namespace/vocabulary_namespace.ex
diff --git a/lib/rdf/utils/resource_classifier.ex b/lib/rdf/vocabulary/resource_classifier.ex
similarity index 98%
rename from lib/rdf/utils/resource_classifier.ex
rename to lib/rdf/vocabulary/resource_classifier.ex
index 2d1940f..2d604f1 100644
--- a/lib/rdf/utils/resource_classifier.ex
+++ b/lib/rdf/vocabulary/resource_classifier.ex
@@ -1,4 +1,4 @@
-defmodule RDF.Utils.ResourceClassifier do
+defmodule RDF.Vocabulary.ResourceClassifier do
   @moduledoc false
 
   alias RDF.Description
diff --git a/test/unit/namespace_test.exs b/test/unit/namespace/namespace_test.exs
similarity index 100%
rename from test/unit/namespace_test.exs
rename to test/unit/namespace/namespace_test.exs
diff --git a/test/unit/nquads_decoder_test.exs b/test/unit/serializations/nquads_decoder_test.exs
similarity index 100%
rename from test/unit/nquads_decoder_test.exs
rename to test/unit/serializations/nquads_decoder_test.exs
diff --git a/test/unit/nquads_encoder_test.exs b/test/unit/serializations/nquads_encoder_test.exs
similarity index 100%
rename from test/unit/nquads_encoder_test.exs
rename to test/unit/serializations/nquads_encoder_test.exs
diff --git a/test/unit/nquads_star_encoder_test.exs b/test/unit/serializations/nquads_star_encoder_test.exs
similarity index 100%
rename from test/unit/nquads_star_encoder_test.exs
rename to test/unit/serializations/nquads_star_encoder_test.exs
diff --git a/test/unit/ntriples_decoder_test.exs b/test/unit/serializations/ntriples_decoder_test.exs
similarity index 100%
rename from test/unit/ntriples_decoder_test.exs
rename to test/unit/serializations/ntriples_decoder_test.exs
diff --git a/test/unit/ntriples_encoder_test.exs b/test/unit/serializations/ntriples_encoder_test.exs
similarity index 100%
rename from test/unit/ntriples_encoder_test.exs
rename to test/unit/serializations/ntriples_encoder_test.exs
diff --git a/test/unit/ntriples_star_decoder_test.exs b/test/unit/serializations/ntriples_star_decoder_test.exs
similarity index 100%
rename from test/unit/ntriples_star_decoder_test.exs
rename to test/unit/serializations/ntriples_star_decoder_test.exs
diff --git a/test/unit/ntriples_star_encoder_test.exs b/test/unit/serializations/ntriples_star_encoder_test.exs
similarity index 100%
rename from test/unit/ntriples_star_encoder_test.exs
rename to test/unit/serializations/ntriples_star_encoder_test.exs
diff --git a/test/unit/turtle_decoder_test.exs b/test/unit/serializations/turtle_decoder_test.exs
similarity index 100%
rename from test/unit/turtle_decoder_test.exs
rename to test/unit/serializations/turtle_decoder_test.exs
diff --git a/test/unit/turtle_encoder_test.exs b/test/unit/serializations/turtle_encoder_test.exs
similarity index 100%
rename from test/unit/turtle_encoder_test.exs
rename to test/unit/serializations/turtle_encoder_test.exs
diff --git a/test/unit/turtle_star_encoder_test.exs b/test/unit/serializations/turtle_star_encoder_test.exs
similarity index 100%
rename from test/unit/turtle_star_encoder_test.exs
rename to test/unit/serializations/turtle_star_encoder_test.exs
diff --git a/test/unit/vocabulary_namespace_test.exs b/test/unit/vocabulary/namespace/vocabulary_namespace_test.exs
similarity index 100%
rename from test/unit/vocabulary_namespace_test.exs
rename to test/unit/vocabulary/namespace/vocabulary_namespace_test.exs