diff --git a/arch/sim/src/nuttx-names.dat b/arch/sim/src/nuttx-names.dat
index 3f3f08402dd..b04b716a03c 100644
--- a/arch/sim/src/nuttx-names.dat
+++ b/arch/sim/src/nuttx-names.dat
@@ -1,3 +1,4 @@
+__errno        NX__errno
 _exit          NX_exit
 accept         NXaccept
 asprintf       NXasprintf