diff --git a/components/newlib/time.c b/components/newlib/time.c
index a021d15eee..22960ab933 100644
--- a/components/newlib/time.c
+++ b/components/newlib/time.c
@@ -153,6 +153,7 @@ int adjtime(const struct timeval *delta, struct timeval *outdelta)
     }
     return 0;
 #else
+    errno = ENOSYS;
     return -1;
 #endif
 }