1 files changed, 6 insertions, 2 deletions
diff --git a/lib/libc/ctype/isupper.c b/lib/libc/ctype/isupper.c
index b46dce41..d831a3fa 100644
--- a/lib/libc/ctype/isupper.c
+++ b/lib/libc/ctype/isupper.c
@@ -1,8 +1,12 @@
-#include <libc.h> // for weak_reference
+#include <ctype.h>     // for isupper, isupper_l, locale_t
+#include <sys/cdefs.h> // for __unused, __weak
 
 int isupper(int c)
 {
 	return (unsigned)c - 'A' < 26;
 }
 
-weak_reference(isupper, isupper_l);
+__weak int isupper_l(int c, locale_t __unused locale)
+{
+	return isupper(c);
+}