diff --git a/contrib/pyln-testing/pyln/testing/utils.py b/contrib/pyln-testing/pyln/testing/utils.py
index a2386bc2d..fb4172a69 100644
--- a/contrib/pyln-testing/pyln/testing/utils.py
+++ b/contrib/pyln-testing/pyln/testing/utils.py
@@ -66,6 +66,7 @@ TEST_NETWORK = env("TEST_NETWORK", 'regtest')
 DEVELOPER = env("DEVELOPER", "0") == "1"
 TEST_DEBUG = env("TEST_DEBUG", "0") == "1"
 SLOW_MACHINE = env("SLOW_MACHINE", "0") == "1"
+DEPRECATED_APIS = env("DEPRECATED_APIS", "0") == "1"
 TIMEOUT = int(env("TIMEOUT", 180 if SLOW_MACHINE else 60))
 
 
@@ -479,7 +480,8 @@ class LightningD(TailableProc):
         opts = {
             'lightning-dir': lightning_dir,
             'addr': '127.0.0.1:{}'.format(port),
-            'allow-deprecated-apis': 'false',
+            'allow-deprecated-apis': '{}'.format("true" if DEPRECATED_APIS
+                                                 else "false"),
             'network': TEST_NETWORK,
             'ignore-fee-limits': 'false',
             'bitcoin-rpcuser': BITCOIND_CONFIG['rpcuser'],