diff --git a/test/fixtures/test_grammars/external_unicode_column_alignment/scanner.c b/test/fixtures/test_grammars/external_unicode_column_alignment/scanner.c
index 13d9f9db..86fb270b 100644
--- a/test/fixtures/test_grammars/external_unicode_column_alignment/scanner.c
+++ b/test/fixtures/test_grammars/external_unicode_column_alignment/scanner.c
@@ -1,4 +1,6 @@
 #include <tree_sitter/parser.h>
+#include <wctype.h>
+#include <string.h>
 
 enum {
   LIST_START,