diff --git a/tests/Main.hs b/tests/Main.hs
index d7431a8..02350fd 100644
--- a/tests/Main.hs
+++ b/tests/Main.hs
@@ -39,3 +39,56 @@ headerParseSpec = do
           parseOnly pTitle "= This is another level 0 title =\n"
           `shouldBe`
           Right (0, "This is another level 0 title")
+
+        it "parses a two-line level 0 title with a full-length underline" $
+          parseOnly pTitle "This is a two-line level 0 title\n\
+                           \================================\n"
+          `shouldBe`
+          Right (0, "This is a two-line level 0 title")
+
+        it "parses a two-line level 0 title with a minimal underline" $
+          parseOnly pTitle "Another two-line level 0 title\n\
+                           \==\n"
+          `shouldBe`
+          Right (0, "Another two-line level 0 title")
+
+        it "parses a one-line level 1 title" $
+          parseOnly pTitle "== Level 1\n" `shouldBe` Right (1, "Level 1")
+
+        it "parses a one-line level 1 title with right-delimiter" $
+          parseOnly pTitle "== Level 1 ==\n" `shouldBe` Right (1, "Level 1")
+
+        it "parses a one-line level 2 title" $
+          parseOnly pTitle "=== Level 2\n" `shouldBe` Right (2, "Level 2")
+
+        it "parses a one-line level 2 title with right-delimiter" $
+          parseOnly pTitle "=== Level 2 ===\n" `shouldBe` Right (2, "Level 2")
+
+        it "parses a one-line level 3 title" $
+          parseOnly pTitle "==== Level 3\n" `shouldBe` Right (3, "Level 3")
+
+        it "parses a one-line level 3 title with right-delimiter" $
+          parseOnly pTitle "==== Level 3 ====\n" `shouldBe` Right (3, "Level 3")
+
+        it "parses a one-line level 4 title" $
+          parseOnly pTitle "===== Level 4\n" `shouldBe` Right (4, "Level 4")
+
+        it "parses a one-line level 4 title with right-delimiter" $
+          parseOnly pTitle "===== Level 4 =====\n" `shouldBe` Right (4, "Level 4")
+
+        it "parses a two-line level 1 title" $
+          parseOnly pTitle "A two-line level 1 title\n--\n"
+          `shouldBe` Right (1, "A two-line level 1 title")
+
+        it "parses a two-line level 2 title" $
+          parseOnly pTitle "A two-line level 2 title\n~~\n"
+          `shouldBe` Right (2, "A two-line level 2 title")
+
+        it "parses a two-line level 3 title" $
+          parseOnly pTitle "A two-line level 3 title\n^^\n"
+          `shouldBe` Right (3, "A two-line level 3 title")
+
+        it "parses a two-line level 4 title" $
+          parseOnly pTitle "A two-line level 4 title\n++\n"
+          `shouldBe` Right (4, "A two-line level 4 title")
+