diff --git a/avatar2/protocols/jlink.py b/avatar2/protocols/jlink.py
index 80187c235b..99abc7eca2 100644
--- a/avatar2/protocols/jlink.py
+++ b/avatar2/protocols/jlink.py
@@ -26,12 +26,12 @@ class JLinkProtocol(Thread):
     :ivar origin:   the target utilizing this protocol
     """
 
-    def __init__(self, serial="12345678", device="ARM7", interface="swd", avatar=None, origin=None):
+    def __init__(self, serial=None, device="ARM7", interface="swd", avatar=None, origin=None):
         self._shutdown = Event()
         self.avatar = avatar
         self._origin = origin
         self.jlink = pylink.JLink()
-        self.jlink.open(serial)
+        self.jlink.open(serial_no=serial)
         if interface == "swd": # swd is more generic than jtag
             self.jlink.set_tif(pylink.enums.JLinkInterfaces.SWD)
         self.log = logging.getLogger('%s.%s' %
diff --git a/avatar2/targets/jlink_target.py b/avatar2/targets/jlink_target.py
index 5f29d0d0b5..d41f390b17 100644
--- a/avatar2/targets/jlink_target.py
+++ b/avatar2/targets/jlink_target.py
@@ -10,7 +10,7 @@
 
 
 class JLinkTarget(Target):
-    def __init__(self, avatar, serial, interface, device, **kwargs):
+    def __init__(self, avatar, serial=None, device="ARM7", interface="swd", **kwargs):
         """
         Create a JLink target instance
         :param avatar: The avatar instance
@@ -39,4 +39,4 @@ def reset(self, halt=True):
         if halt:
             self.state = TargetStates.STOPPED
         else:
-            self.state = TargetStates.RUNNING
\ No newline at end of file
+            self.state = TargetStates.RUNNING
diff --git a/handbook/0x02_targets.md b/handbook/0x02_targets.md
index 89e4facace..e4d3fe38bb 100644
--- a/handbook/0x02_targets.md
+++ b/handbook/0x02_targets.md
@@ -106,7 +106,7 @@ Easy to use. For example, with Segger JLink hardware devices, developers do not
 
 | name                | type  | default | purpose                                                                                         |
 |---------------------|-------|---------|-------------------------------------------------------------------------------------------------|
-| serial              | str   |"123456" | JLink emulator serial number. JLink Onboard provides default number "123456" |
+| serial              | str   | None    | JLink emulator serial number. Default None, which leaves JLink the choice where to connect to. |
 | device              | str   | "ARM7"  | Device name which should be avaliable for used JLink emulator                |
 | interface           | str   | "swd"   | "swd" or "jtag" interface                                                    |