diff --git a/corpus/subject.txt b/corpus/subject.txt
index 1e0a7f5..747c2ae 100644
--- a/corpus/subject.txt
+++ b/corpus/subject.txt
@@ -136,3 +136,14 @@ feat!: allow provided config object to extend other configs
       (type))
     (overflow)))
 
+================================================================================
+fix #36
+================================================================================
+feat(test):
+--------------------------------------------------------------------------------
+
+(source
+  (ERROR
+    (prefix
+      (type)
+      (scope))))
diff --git a/src/scanner.c b/src/scanner.c
index 92d391f..a122193 100644
--- a/src/scanner.c
+++ b/src/scanner.c
@@ -59,8 +59,13 @@ bool tree_sitter_gitcommit_external_scanner_scan(void *payload, TSLexer *lexer,
   if (valid_symbols[CONVENTIONNAL_SUBJECT]) {
     lexer->result_symbol = CONVENTIONNAL_SUBJECT;
 
+    if (lexer->lookahead == '\n' || lexer->lookahead == '\r' ||
+        lexer->lookahead == '\0') {
+      return false;
+    }
+
     while (lexer->lookahead != '\n' && lexer->lookahead != '\r' &&
-           50 > lexer->get_column(lexer)) {
+           lexer->lookahead != '\0' && 50 > lexer->get_column(lexer)) {
       lexer->advance(lexer, false);
     }