diff --git a/config/linux/x86_64/headers.txt b/config/linux/x86_64/headers.txt
index b44681a..550f172 100644
--- a/config/linux/x86_64/headers.txt
+++ b/config/linux/x86_64/headers.txt
@@ -1,5 +1,6 @@
 set(TARGET_PUBLIC_HEADERS
     libc.include.assert_h
+    libc.include.ctype
     libc.include.errno
     libc.include.math
     libc.include.signal