2 files changed, 7 insertions, 1 deletions
diff --git a/test/functional/test_framework/test_node.py b/test/functional/test_framework/test_node.py
index 40681790b9..e5c77ae5fa 100755
--- a/test/functional/test_framework/test_node.py
+++ b/test/functional/test_framework/test_node.py
@@ -30,6 +30,7 @@ from .util import (
     rpc_url,
     wait_until,
     p2p_port,
+    EncodeDecimal,
 )
 
 BITCOIND_PROC_WAIT_TIMEOUT = 60
@@ -489,7 +490,7 @@ def arg_to_cli(arg):
     if isinstance(arg, bool):
         return str(arg).lower()
     elif isinstance(arg, dict) or isinstance(arg, list):
-        return json.dumps(arg)
+        return json.dumps(arg, default=EncodeDecimal)
     else:
         return str(arg)
 
diff --git a/test/functional/test_framework/util.py b/test/functional/test_framework/util.py
index 4d7967273a..5bb73aee7e 100644
--- a/test/functional/test_framework/util.py
+++ b/test/functional/test_framework/util.py
@@ -190,6 +190,11 @@ def check_json_precision():
     if satoshis != 2000000000000003:
         raise RuntimeError("JSON encode/decode loses precision")
 
+def EncodeDecimal(o):
+    if isinstance(o, Decimal):
+        return str(o)
+    raise TypeError(repr(o) + " is not JSON serializable")
+
 def count_bytes(hex_string):
     return len(bytearray.fromhex(hex_string))