diff --git a/tests/utils.py b/tests/utils.py
index cf66f951b..016b880a5 100644
--- a/tests/utils.py
+++ b/tests/utils.py
@@ -253,7 +253,7 @@ class LightningD(TailableProc):
             self.cmd_line += ['--dev-broadcast-interval=1000']
             if not random_hsm:
                 self.cmd_line += ['--dev-hsm-seed={}'.format(seed.hex())]
-        self.cmd_line += ["--{}={}".format(k, v) for k, v in LIGHTNINGD_CONFIG.items()]
+        self.cmd_line += ["--{}={}".format(k, v) for k, v in sorted(LIGHTNINGD_CONFIG.items())]
         self.prefix = 'lightningd(%d)' % (port)
 
         if not os.path.exists(lightning_dir):