diff --git a/test/Core/NewlineSpec.hs b/test/Core/NewlineSpec.hs
new file mode 100644
index 00000000..59bb68fd
--- /dev/null
+++ b/test/Core/NewlineSpec.hs
@@ -0,0 +1,17 @@
+module Core.NewlineSpec (spec) where
+
+import JbeamEdit.Core.Newline (detectNewline)
+import System.IO (Newline (..))
+import Test.Hspec
+
+spec :: Spec
+spec =
+  describe "detectNewline" $ do
+    it "detects LF for unix line endings" $
+      detectNewline "a\nb\n" `shouldBe` LF
+    it "detects CRLF for windows line endings" $
+      detectNewline "a\r\nb\r\n" `shouldBe` CRLF
+    it "detects CRLF when line endings are mixed" $
+      detectNewline "a\r\nb\n" `shouldBe` CRLF
+    it "defaults to LF when there is no line ending" $
+      detectNewline "abc" `shouldBe` LF