diff --git a/components/newlib/time.c b/components/newlib/time.c
index 73fc04e5cc..638beb19a4 100644
--- a/components/newlib/time.c
+++ b/components/newlib/time.c
@@ -139,6 +139,7 @@ int adjtime(const struct timeval *delta, struct timeval *outdelta)
     }
     return 0;
 #else
+    errno = ENOSYS;
     return -1;
 #endif
 }