diff --git a/src/Language/GraphQL/AST/Encoder.hs b/src/Language/GraphQL/AST/Encoder.hs
index ab17929..b5265cc 100644
--- a/src/Language/GraphQL/AST/Encoder.hs
+++ b/src/Language/GraphQL/AST/Encoder.hs
@@ -135,6 +135,13 @@ typeDefinition formatter = \case
         <> optempty (directives formatter) directives'
         <> eitherFormat formatter " " ""
         <> unionMemberTypes formatter members'
+    Full.EnumTypeDefinition description' name' directives' members'
+        -> optempty (description formatter) description'
+        <> "enum "
+        <> Lazy.Text.fromStrict name'
+        <> optempty (directives formatter) directives'
+        <> eitherFormat formatter " " ""
+        <> bracesList formatter (enumValueDefinition formatter) members'
     _typeDefinition' -> "" -- TODO: Types missing.
   where
     nextFormatter = incrementIndent formatter
@@ -160,6 +167,20 @@ unionMemberTypes formatter (Full.UnionMemberTypes memberTypes)
         $ (("\n" <> indentSymbol <> "| ") <>) . Lazy.Text.fromStrict
         <$> toList memberTypes
 
+enumValueDefinition :: Formatter -> Full.EnumValueDefinition -> Lazy.Text
+enumValueDefinition (Pretty _) enumValue =
+    let Full.EnumValueDefinition description' name' directives' = enumValue
+        formatter = Pretty 1
+     in description formatter description'
+        <> indentLine formatter
+        <> Lazy.Text.fromStrict name'
+        <> directives formatter directives'
+enumValueDefinition Minified enumValue =
+    let Full.EnumValueDefinition description' name' directives' = enumValue
+     in description Minified description'
+        <> Lazy.Text.fromStrict name'
+        <> directives Minified directives'
+
 description :: Formatter -> Full.Description -> Lazy.Text.Text
 description _formatter (Full.Description Nothing) = ""
 description formatter (Full.Description (Just description')) =
diff --git a/tests/Language/GraphQL/AST/EncoderSpec.hs b/tests/Language/GraphQL/AST/EncoderSpec.hs
index 5116c0e..a4ba470 100644
--- a/tests/Language/GraphQL/AST/EncoderSpec.hs
+++ b/tests/Language/GraphQL/AST/EncoderSpec.hs
@@ -218,7 +218,7 @@ spec = do
                 actual = typeSystemDefinition pretty definition'
              in actual `shouldBe` expected
 
-        it "encodes an enum definition" $
+        it "encodes an union definition" $
             let definition' = Full.TypeDefinition
                     $ Full.UnionTypeDefinition mempty "SearchResult" mempty
                     $ Full.UnionMemberTypes ["Photo", "Person"]
@@ -229,3 +229,23 @@ spec = do
                 |]
                 actual = typeSystemDefinition pretty definition'
              in actual `shouldBe` expected
+
+        it "encodes an enum definition" $
+            let values =
+                    [ Full.EnumValueDefinition mempty "NORTH" mempty
+                    , Full.EnumValueDefinition mempty "EAST" mempty
+                    , Full.EnumValueDefinition mempty "SOUTH" mempty
+                    , Full.EnumValueDefinition mempty "WEST" mempty
+                    ]
+                definition' = Full.TypeDefinition
+                    $ Full.EnumTypeDefinition mempty "Direction" mempty values
+                expected = [gql|
+                  enum Direction {
+                    NORTH
+                    EAST
+                    SOUTH
+                    WEST
+                  }
+                |]
+                actual = typeSystemDefinition pretty definition'
+             in actual `shouldBe` expected