diff --git a/tests/Language/GraphQL/AST/EncoderSpec.hs b/tests/Language/GraphQL/AST/EncoderSpec.hs
index 3fa6a02..37c6302 100644
--- a/tests/Language/GraphQL/AST/EncoderSpec.hs
+++ b/tests/Language/GraphQL/AST/EncoderSpec.hs
@@ -11,6 +11,7 @@ import Language.GraphQL.TH
 import Test.Hspec (Spec, context, describe, it, shouldBe, shouldStartWith, shouldEndWith, shouldNotContain)
 import Test.QuickCheck (choose, oneof, forAll)
 import qualified Data.Text.Lazy as Text.Lazy
+import qualified Language.GraphQL.AST.DirectiveLocation as DirectiveLocation
 
 spec :: Spec
 spec = do
@@ -267,3 +268,26 @@ spec = do
                 |]
                 actual = typeSystemDefinition pretty definition'
              in actual `shouldBe` expected
+
+        context "directive definition" $ do
+            it "encodes a directive definition" $ do
+                let definition' = Full.DirectiveDefinition mempty "example" mempty False
+                        $ pure
+                        $ DirectiveLocation.ExecutableDirectiveLocation DirectiveLocation.Field
+                    expected = [gql|
+                    @example() on
+                      | FIELD
+                    |]
+                    actual = typeSystemDefinition pretty definition'
+                 in actual `shouldBe` expected
+
+            it "encodes a repeatable directive definition" $ do
+                let definition' = Full.DirectiveDefinition mempty "example" mempty True
+                        $ pure
+                        $ DirectiveLocation.ExecutableDirectiveLocation DirectiveLocation.Field
+                    expected = [gql|
+                    @example() repeatable on
+                      | FIELD
+                    |]
+                    actual = typeSystemDefinition pretty definition'
+                 in actual `shouldBe` expected