1 files changed, 1 insertions, 1 deletions
diff --git a/build.c b/build.c
index 6046b86..110a3c0 100644
--- a/build.c
+++ b/build.c
@@ -159,7 +159,7 @@ static int parse_nonnegative_integer(char32_t **str, char32_t *end) {
 // could this character (reasonably) appear in a source file path?
 static bool is_source_path(char32_t c) {
 	const char *allowed_ascii_symbols_in_path = "./\\-_:";
-	return c > CHAR_MAX || isalnum((char)c)
+	return c > CHAR_MAX || is32_alnum((wint_t)c)
 		|| strchr(allowed_ascii_symbols_in_path, (char)c);
 }