1 files changed, 21 insertions, 15 deletions
diff --git a/src/construct/heading_setext.rs b/src/construct/heading_setext.rs
index 4e6345a..1f6270a 100644
--- a/src/construct/heading_setext.rs
+++ b/src/construct/heading_setext.rs
@@ -85,16 +85,20 @@ pub fn start(tokenizer: &mut Tokenizer) -> State {
             .name
                 == Name::Paragraph)
     {
-        tokenizer.attempt(State::Next(StateName::HeadingSetextBefore), State::Nok);
-        State::Retry(space_or_tab_min_max(
-            tokenizer,
-            0,
-            if tokenizer.parse_state.constructs.code_indented {
-                TAB_SIZE - 1
-            } else {
-                usize::MAX
-            },
-        ))
+        if matches!(tokenizer.current, Some(b'\t' | b' ')) {
+            tokenizer.attempt(State::Next(StateName::HeadingSetextBefore), State::Nok);
+            State::Retry(space_or_tab_min_max(
+                tokenizer,
+                0,
+                if tokenizer.parse_state.constructs.code_indented {
+                    TAB_SIZE - 1
+                } else {
+                    usize::MAX
+                },
+            ))
+        } else {
+            State::Retry(StateName::HeadingSetextBefore)
+        }
     } else {
         State::Nok
     }
@@ -132,11 +136,13 @@ pub fn inside(tokenizer: &mut Tokenizer) -> State {
     } else {
         tokenizer.tokenize_state.marker = 0;
         tokenizer.exit(Name::HeadingSetextUnderline);
-        tokenizer.attempt(
-            State::Next(StateName::HeadingSetextAfter),
-            State::Next(StateName::HeadingSetextAfter),
-        );
-        State::Retry(space_or_tab(tokenizer))
+
+        if matches!(tokenizer.current, Some(b'\t' | b' ')) {
+            tokenizer.attempt(State::Next(StateName::HeadingSetextAfter), State::Nok);
+            State::Retry(space_or_tab(tokenizer))
+        } else {
+            State::Retry(StateName::HeadingSetextAfter)
+        }
     }
 }