diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8eee4240cc..c20ce375f5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,8 @@
 
 ## Unreleased
 
+- Bug Fix: [Validate type references for invalid wrapped types](https://github.com/absinthe-graphql/absinthe/pull/1195)
+- Feature: [Add `specifiedBy` type system directive](https://github.com/absinthe-graphql/absinthe/pull/1193)
 - Bug Fix: [Object type extensions may be empty](https://github.com/absinthe-graphql/absinthe/pull/1228)
 - Bug Fix: [Validate input object not being an Enum](https://github.com/absinthe-graphql/absinthe/pull/1231)
 - Bug Fix: [Deduplicate directives when building schema](https://github.com/absinthe-graphql/absinthe/pull/1242)
diff --git a/lib/absinthe/phase/document/validation/known_directives.ex b/lib/absinthe/phase/document/validation/known_directives.ex
index e1d978ee7b..32c9a9a36c 100644
--- a/lib/absinthe/phase/document/validation/known_directives.ex
+++ b/lib/absinthe/phase/document/validation/known_directives.ex
@@ -63,7 +63,7 @@ defmodule Absinthe.Phase.Document.Validation.KnownDirectives do
   defp error_unknown(node) do
     %Phase.Error{
       phase: __MODULE__,
-      message: "Unknown directive `#{node.name}'.",
+      message: "Unknown directive `#{node.name}`.",
       locations: [node.source_location]
     }
   end
@@ -74,7 +74,7 @@ defmodule Absinthe.Phase.Document.Validation.KnownDirectives do
 
     %Phase.Error{
       phase: __MODULE__,
-      message: "Directive `#{node.name}' may not be used on #{placement_name}.",
+      message: "Directive `#{node.name}` may not be used on #{placement_name}.",
       locations: [node.source_location]
     }
   end
diff --git a/lib/absinthe/schema/notation.ex b/lib/absinthe/schema/notation.ex
index 6628bbaef4..3d5b2b08a7 100644
--- a/lib/absinthe/schema/notation.ex
+++ b/lib/absinthe/schema/notation.ex
@@ -1606,7 +1606,7 @@ defmodule Absinthe.Schema.Notation do
     attrs =
       attrs
       |> Keyword.put(:identifier, identifier)
-      |> Keyword.put_new(:name, to_string(identifier))
+      |> Keyword.put_new(:name, default_name(Schema.DirectiveDefinition, identifier))
       |> Keyword.update(:description, nil, &wrap_in_unquote/1)
 
     scoped_def(env, Schema.DirectiveDefinition, identifier, attrs, block)
@@ -1985,6 +1985,11 @@ defmodule Absinthe.Schema.Notation do
     |> Atom.to_string()
   end
 
+  defp default_name(Schema.DirectiveDefinition, identifier) do
+    identifier
+    |> Atom.to_string()
+  end
+
   defp default_name(_, identifier) do
     identifier
     |> Atom.to_string()
diff --git a/lib/absinthe/schema/prototype/notation.ex b/lib/absinthe/schema/prototype/notation.ex
index e06dd0ced6..68dce53c2e 100644
--- a/lib/absinthe/schema/prototype/notation.ex
+++ b/lib/absinthe/schema/prototype/notation.ex
@@ -34,6 +34,17 @@ defmodule Absinthe.Schema.Prototype.Notation do
         expand &__MODULE__.expand_deprecate/2
       end
 
+      directive :specified_by do
+        description "Exposes a URL that specifies the behavior of this scalar."
+
+        repeatable false
+
+        arg :url, non_null(:string),
+          description: "The URL that specifies the behavior of this scalar."
+
+        on [:scalar]
+      end
+
       def pipeline(pipeline) do
         pipeline
         |> Absinthe.Pipeline.without(Absinthe.Phase.Schema.Validation.QueryTypeMustBeObject)
diff --git a/lib/absinthe/type/built_ins/introspection.ex b/lib/absinthe/type/built_ins/introspection.ex
index 4923acc230..5ffc20fe53 100644
--- a/lib/absinthe/type/built_ins/introspection.ex
+++ b/lib/absinthe/type/built_ins/introspection.ex
@@ -54,7 +54,11 @@ defmodule Absinthe.Type.BuiltIns.Introspection do
   object :__directive do
     description "Represents a directive"
 
-    field :name, non_null(:string)
+    field :name,
+      type: non_null(:string),
+      resolve: fn _, %{adapter: adapter, source: source} ->
+        {:ok, adapter.to_external_name(source.name, :field)}
+      end
 
     field :description, :string
 
diff --git a/test/absinthe/integration/execution/introspection/directives_test.exs b/test/absinthe/integration/execution/introspection/directives_test.exs
index bd779fad54..764afc0c1c 100644
--- a/test/absinthe/integration/execution/introspection/directives_test.exs
+++ b/test/absinthe/integration/execution/introspection/directives_test.exs
@@ -72,6 +72,23 @@ defmodule Elixir.Absinthe.Integration.Execution.Introspection.DirectivesTest do
                       "onFragment" => true,
                       "onOperation" => false,
                       "isRepeatable" => false
+                    },
+                    %{
+                      "isRepeatable" => false,
+                      "locations" => ["SCALAR"],
+                      "name" => "specifiedBy",
+                      "onField" => false,
+                      "onFragment" => false,
+                      "onOperation" => false,
+                      "args" => [
+                        %{
+                          "name" => "url",
+                          "type" => %{
+                            "kind" => "NON_NULL",
+                            "ofType" => %{"kind" => "SCALAR", "name" => "String"}
+                          }
+                        }
+                      ]
                     }
                   ]
                 }
diff --git a/test/absinthe/introspection_test.exs b/test/absinthe/introspection_test.exs
index 391eddfcf9..3575efb9d1 100644
--- a/test/absinthe/introspection_test.exs
+++ b/test/absinthe/introspection_test.exs
@@ -71,6 +71,16 @@ defmodule Absinthe.IntrospectionTest do
                         "onField" => true,
                         "onFragment" => true,
                         "onOperation" => false
+                      },
+                      %{
+                        "description" =>
+                          "Exposes a URL that specifies the behavior of this scalar.",
+                        "isRepeatable" => false,
+                        "locations" => ["SCALAR"],
+                        "name" => "specifiedBy",
+                        "onField" => false,
+                        "onFragment" => false,
+                        "onOperation" => false
                       }
                     ]
                   }
diff --git a/test/absinthe/phase/document/validation/known_directives_test.exs b/test/absinthe/phase/document/validation/known_directives_test.exs
index f20ce5782e..5d6da639f9 100644
--- a/test/absinthe/phase/document/validation/known_directives_test.exs
+++ b/test/absinthe/phase/document/validation/known_directives_test.exs
@@ -5,12 +5,12 @@ defmodule Absinthe.Phase.Document.Validation.KnownDirectivesTest do
     phase: @phase,
     async: true
 
-  alias Absinthe.{Blueprint}
+  alias Absinthe.Blueprint
 
   def unknown_directive(name, line) do
     bad_value(
       Blueprint.Directive,
-      "Unknown directive `#{name}'.",
+      "Unknown directive `#{name}`.",
       line,
       name: name
     )
@@ -19,7 +19,7 @@ defmodule Absinthe.Phase.Document.Validation.KnownDirectivesTest do
   def misplaced_directive(name, placement, line) do
     bad_value(
       Blueprint.Directive,
-      "Directive `#{name}' may not be used on #{placement}.",
+      "Directive `#{name}` may not be used on #{placement}.",
       line,
       name: name
     )
diff --git a/test/absinthe/strict_schema_test.exs b/test/absinthe/strict_schema_test.exs
index 03eda113c4..d62592a0bf 100644
--- a/test/absinthe/strict_schema_test.exs
+++ b/test/absinthe/strict_schema_test.exs
@@ -34,7 +34,7 @@ defmodule Absinthe.StrictSchemaTest do
       variables = %{"input" => %{"naiveDatetime" => "2017-01-27T20:31:55"}}
 
       assert_error_message(
-        "Unknown directive `foo_bar_directive'.",
+        "Unknown directive `foo_bar_directive`.",
         run(document, Absinthe.Fixtures.StrictSchema,
           adapter: Absinthe.Adapter.StrictLanguageConventions,
           variables: variables