diff --git a/scripts/west_commands/runners/ezflashcli.py b/scripts/west_commands/runners/ezflashcli.py
index ca3c226dbbf..393c710e0b0 100644
--- a/scripts/west_commands/runners/ezflashcli.py
+++ b/scripts/west_commands/runners/ezflashcli.py
@@ -12,7 +12,7 @@ DEFAULT_EZFLASHCLI = "ezFlashCLI"
 class EzFlashCliBinaryRunner(ZephyrBinaryRunner):
     '''Runner front-end for ezFlashCLI'''
 
-    def __init__(self, cfg, tool, dev_id=None, tool_opt=[], erase=False, reset=True):
+    def __init__(self, cfg, tool, dev_id=None, tool_opt=None, erase=False, reset=True):
         super().__init__(cfg)
         self.bin_ = cfg.bin_file
 
@@ -22,8 +22,9 @@ class EzFlashCliBinaryRunner(ZephyrBinaryRunner):
         self.reset = bool(reset)
 
         self.tool_opt = []
-        for opts in [shlex.split(opt) for opt in tool_opt]:
-            self.tool_opt += opts
+        if tool_opt is not None:
+            for opts in [shlex.split(opt) for opt in tool_opt]:
+                self.tool_opt += opts
 
     @classmethod
     def name(cls):
diff --git a/scripts/west_commands/runners/jlink.py b/scripts/west_commands/runners/jlink.py
index 2aedba0a37e..d2d8cda6c68 100644
--- a/scripts/west_commands/runners/jlink.py
+++ b/scripts/west_commands/runners/jlink.py
@@ -58,7 +58,7 @@ class JLinkBinaryRunner(ZephyrBinaryRunner):
                  gdb_host='',
                  gdb_port=DEFAULT_JLINK_GDB_PORT,
                  rtt_port=DEFAULT_JLINK_RTT_PORT,
-                 tui=False, tool_opt=[]):
+                 tui=False, tool_opt=None):
         super().__init__(cfg)
         self.file = cfg.file
         self.file_type = cfg.file_type
@@ -82,8 +82,9 @@ class JLinkBinaryRunner(ZephyrBinaryRunner):
         self.rtt_port = rtt_port
 
         self.tool_opt = []
-        for opts in [shlex.split(opt) for opt in tool_opt]:
-            self.tool_opt += opts
+        if tool_opt is not None:
+            for opts in [shlex.split(opt) for opt in tool_opt]:
+                self.tool_opt += opts
 
     @classmethod
     def name(cls):
diff --git a/scripts/west_commands/runners/linkserver.py b/scripts/west_commands/runners/linkserver.py
index 7cf419a705c..4d0a4a15f57 100644
--- a/scripts/west_commands/runners/linkserver.py
+++ b/scripts/west_commands/runners/linkserver.py
@@ -29,8 +29,8 @@ class LinkServerBinaryRunner(ZephyrBinaryRunner):
                  gdb_host='',
                  gdb_port=DEFAULT_LINKSERVER_GDB_PORT,
                  semihost_port=DEFAULT_LINKSERVER_SEMIHOST_PORT,
-                 override=[],
-                 tui=False, tool_opt=[]):
+                 override=None,
+                 tui=False, tool_opt=None):
         super().__init__(cfg)
         self.file = cfg.file
         self.file_type = cfg.file_type
@@ -48,12 +48,13 @@ class LinkServerBinaryRunner(ZephyrBinaryRunner):
         self.gdb_port = gdb_port
         self.semihost_port = semihost_port
         self.tui_arg = ['-tui'] if tui else []
-        self.override = override
+        self.override = override if override else []
         self.override_cli = self._build_override_cli()
 
         self.tool_opt = []
-        for opts in [shlex.split(opt) for opt in tool_opt]:
-            self.tool_opt += opts
+        if tool_opt is not None:
+            for opts in [shlex.split(opt) for opt in tool_opt]:
+                self.tool_opt += opts
 
     @classmethod
     def name(cls):
diff --git a/scripts/west_commands/runners/nrf_common.py b/scripts/west_commands/runners/nrf_common.py
index be732673f52..ec6baf29495 100644
--- a/scripts/west_commands/runners/nrf_common.py
+++ b/scripts/west_commands/runners/nrf_common.py
@@ -76,7 +76,7 @@ class NrfBinaryRunner(ZephyrBinaryRunner):
     '''Runner front-end base class for nrf tools.'''
 
     def __init__(self, cfg, family, softreset, dev_id, erase=False,
-                 reset=True, tool_opt=[], force=False, recover=False):
+                 reset=True, tool_opt=None, force=False, recover=False):
         super().__init__(cfg)
         self.hex_ = cfg.hex_file
         if family and not family.endswith('_FAMILY'):
@@ -93,8 +93,9 @@ class NrfBinaryRunner(ZephyrBinaryRunner):
         self.suit_starter = False
 
         self.tool_opt = []
-        for opts in [shlex.split(opt) for opt in tool_opt]:
-            self.tool_opt += opts
+        if tool_opt is not None:
+            for opts in [shlex.split(opt) for opt in tool_opt]:
+                self.tool_opt += opts
 
     @classmethod
     def capabilities(cls):
diff --git a/scripts/west_commands/runners/nrfjprog.py b/scripts/west_commands/runners/nrfjprog.py
index ce135222ad0..ae6fec6c5b9 100644
--- a/scripts/west_commands/runners/nrfjprog.py
+++ b/scripts/west_commands/runners/nrfjprog.py
@@ -19,7 +19,7 @@ class NrfJprogBinaryRunner(NrfBinaryRunner):
     '''Runner front-end for nrfjprog.'''
 
     def __init__(self, cfg, family, softreset, dev_id, erase=False,
-                 reset=True, tool_opt=[], force=False, recover=False,
+                 reset=True, tool_opt=None, force=False, recover=False,
                  qspi_ini=None):
 
         super().__init__(cfg, family, softreset, dev_id, erase, reset,
diff --git a/scripts/west_commands/runners/nrfutil.py b/scripts/west_commands/runners/nrfutil.py
index 165c03f2feb..d2c3c53a5dd 100644
--- a/scripts/west_commands/runners/nrfutil.py
+++ b/scripts/west_commands/runners/nrfutil.py
@@ -17,7 +17,7 @@ class NrfUtilBinaryRunner(NrfBinaryRunner):
     '''Runner front-end for nrfutil.'''
 
     def __init__(self, cfg, family, softreset, dev_id, erase=False,
-                 reset=True, tool_opt=[], force=False, recover=False,
+                 reset=True, tool_opt=None, force=False, recover=False,
                  suit_starter=False):
 
         super().__init__(cfg, family, softreset, dev_id, erase, reset,