diff --git a/include/CMakeLists.txt b/include/CMakeLists.txt
index 6bd75915d..be0e10d50 100644
--- a/include/CMakeLists.txt
+++ b/include/CMakeLists.txt
@@ -2,6 +2,7 @@ set(files
   __bit_reference
   __bsd_locale_defaults.h
   __bsd_locale_fallbacks.h
+  __errc
   __debug
   __functional_03
   __functional_base