diff --git a/src/caosdb/connection/connection.py b/src/caosdb/connection/connection.py
index 08723bfe45e968fe09ad9280aab00e296ded6c60..544dff28bf9bf83975fdeded7e127fcb305d7456 100644
--- a/src/caosdb/connection/connection.py
+++ b/src/caosdb/connection/connection.py
@@ -172,7 +172,7 @@ class _DefaultCaosDBServerConnection(CaosDBServerConnection):
             print("*** Warning! ***\n"
                   "Insecure SSL mode, certificate will not be checked! "
                   "Please consider removing the `ssl_insecure` configuration option.\n"
-                  "****************")
+                  "****************", file=sys.stderr)
             context.verify_mode = ssl.CERT_NONE
 
         if (not context.verify_mode == ssl.CERT_NONE and