diff --git a/pymodbus/client/base.py b/pymodbus/client/base.py
index dbf0976e15..fccf7ca346 100644
--- a/pymodbus/client/base.py
+++ b/pymodbus/client/base.py
@@ -85,7 +85,7 @@ def __init__(  # pylint: disable=too-many-arguments
         setup_params = CommParams(
             comm_type=kwargs.get("CommType"),
             comm_name="comm",
-            source_address=kwargs.get("source_address", ("localhost", 0)),
+            source_address=kwargs.get("source_address", ("127.0.0.1", 0)),
             reconnect_delay=reconnect_delay,
             reconnect_delay_max=reconnect_delay_max,
             timeout_connect=timeout,
diff --git a/pymodbus/transport/transport.py b/pymodbus/transport/transport.py
index 50cfc076b9..7762b77add 100644
--- a/pymodbus/transport/transport.py
+++ b/pymodbus/transport/transport.py
@@ -35,9 +35,9 @@ class CommParams:
     reconnect_delay: float = None
     reconnect_delay_max: float = None
     timeout_connect: float = None
-    host: str = "localhost"
+    host: str = "127.0.0.1"
     port: int = 0
-    source_address: tuple[str, int] = ("localhost", 0)
+    source_address: tuple[str, int] = ("127.0.0.1", 0)
 
     # tls
     sslctx: ssl.SSLContext = None
@@ -93,7 +93,7 @@ class ModbusProtocol(asyncio.BaseProtocol):
 
     Host/Port/SourceAddress explanation:
     - SourceAddress:
-        - server: (host, port) to listen on (default is ("localhost", 502/802))
+        - server: (host, port) to listen on (default is ("127.0.0.1", 502/802))
         - server serial: (host, _) to open/connect and listen on
         - client: (Bind local part to interface (default is local interface)
         - client serial: (host, _) to open/connect and listen on