diff --git a/aprsd/client/drivers/aprsis.py b/aprsd/client/drivers/aprsis.py
index 41e6e61..461ba27 100644
--- a/aprsd/client/drivers/aprsis.py
+++ b/aprsd/client/drivers/aprsis.py
@@ -157,7 +157,12 @@ class APRSISDriver:
         return self._client.server_string
 
     @property
-    def keepalive(self):
+    def keepalive(self) -> datetime.datetime:
+        """Get the keepalive timestamp.
+
+        Returns:
+            datetime.datetime: Last keepalive timestamp
+        """
         if not self._client:
             return datetime.datetime.now()
         return self._client.aprsd_keepalive
diff --git a/aprsd/client/drivers/kiss_common.py b/aprsd/client/drivers/kiss_common.py
index 08236e0..ed63d72 100644
--- a/aprsd/client/drivers/kiss_common.py
+++ b/aprsd/client/drivers/kiss_common.py
@@ -25,7 +25,7 @@ class KISSDriver(metaclass=trace.TraceWrapperMetaclass):
     packets_sent = 0
     last_packet_sent = None
     last_packet_received = None
-    keepalive = None
+    _keepalive = None
 
     # timeout in seconds
     select_timeout = 1
@@ -38,7 +38,16 @@ class KISSDriver(metaclass=trace.TraceWrapperMetaclass):
         """
         super().__init__()
         self._connected = False
-        self.keepalive = datetime.datetime.now()
+        self._keepalive = datetime.datetime.now()
+
+    @property
+    def keepalive(self) -> datetime.datetime:
+        """Get the keepalive timestamp.
+
+        Returns:
+            datetime.datetime: Last keepalive timestamp
+        """
+        return self._keepalive
 
     def login_success(self) -> bool:
         """There is no login for KISS."""
@@ -153,7 +162,7 @@ class KISSDriver(metaclass=trace.TraceWrapperMetaclass):
             Dict containing client statistics
         """
         if serializable:
-            keepalive = self.keepalive.isoformat()
+            keepalive = self._keepalive.isoformat() if self._keepalive else 'None'
             if self.last_packet_sent:
                 last_packet_sent = self.last_packet_sent.isoformat()
             else:
@@ -163,7 +172,7 @@ class KISSDriver(metaclass=trace.TraceWrapperMetaclass):
             else:
                 last_packet_received = 'None'
         else:
-            keepalive = self.keepalive
+            keepalive = self._keepalive
             last_packet_sent = self.last_packet_sent
             last_packet_received = self.last_packet_received
 
diff --git a/aprsd/client/drivers/serialkiss.py b/aprsd/client/drivers/serialkiss.py
index fdc8213..97467be 100644
--- a/aprsd/client/drivers/serialkiss.py
+++ b/aprsd/client/drivers/serialkiss.py
@@ -50,7 +50,7 @@ class SerialKISSDriver(KISSDriver):
         """
         super().__init__()
         self._connected = False
-        self.keepalive = datetime.datetime.now()
+        # keepalive is set in parent KISSDriver.__init__()
         # This is initialized in setup_connection()
         self.socket = None
 
diff --git a/aprsd/client/drivers/tcpkiss.py b/aprsd/client/drivers/tcpkiss.py
index ba2135c..976ccbe 100644
--- a/aprsd/client/drivers/tcpkiss.py
+++ b/aprsd/client/drivers/tcpkiss.py
@@ -55,7 +55,7 @@ class TCPKISSDriver(KISSDriver):
         """
         super().__init__()
         self._connected = False
-        self.keepalive = datetime.datetime.now()
+        # keepalive is set in parent KISSDriver.__init__()
         # This is initialized in setup_connection()
         self.socket = None
 
diff --git a/tests/client/drivers/test_tcpkiss_driver.py b/tests/client/drivers/test_tcpkiss_driver.py
index f9f0d28..f2f8f80 100644
--- a/tests/client/drivers/test_tcpkiss_driver.py
+++ b/tests/client/drivers/test_tcpkiss_driver.py
@@ -270,7 +270,7 @@ class TestTCPKISSDriver(unittest.TestCase):
 
     def test_stats_serializable(self):
         """Test stats with serializable=True converts datetime to ISO format."""
-        self.driver.keepalive = datetime.datetime.now()
+        self.driver._keepalive = datetime.datetime.now()
 
         stats = self.driver.stats(serializable=True)