diff --git a/ros2caret/verb/caret_record_init.py b/ros2caret/verb/caret_record_init.py
index 37248501..3ee2e3d6 100644
--- a/ros2caret/verb/caret_record_init.py
+++ b/ros2caret/verb/caret_record_init.py
@@ -49,6 +49,8 @@ def init(
     ros_events: List[str],
     kernel_events: List[str],
     context_fields: List[str],
+    subbuffer_size_ust: int,
+    subbuffer_size_kernel: int,
     display_list: bool = False,
     append_trace: bool = True,
 ) -> bool:
@@ -66,6 +68,8 @@ def init(
     :param kernel_events: list of kernel events to enable
     :param context_fields: list of context fields to enable
     :param display_list: whether to display list(s) of enabled events and context names
+    :param subbuffer_size_ust: the size of the subbuffers for userspace events
+    :param subbuffer_size_kernel: the size of the subbuffers for kernel events
     :return: True if successful, False otherwise
     """
     # Check if LTTng is installed right away before printing anything
@@ -107,6 +111,8 @@ def init(
             ros_events=ros_events,
             kernel_events=kernel_events,
             context_fields=context_fields,
+            subbuffer_size_ust=subbuffer_size_ust,
+            subbuffer_size_kernel=subbuffer_size_kernel,
         )
     # for humble
     else:
diff --git a/ros2caret/verb/record.py b/ros2caret/verb/record.py
index 0c104b2d..ad2fee90 100644
--- a/ros2caret/verb/record.py
+++ b/ros2caret/verb/record.py
@@ -134,6 +134,18 @@ def add_arguments(self, parser, cli_name):
         parser.add_argument(
             '--light', dest='light_mode', action='store_true',
             help='light mode (record high level events only)')
+        parser.add_argument(
+            '--subbuffer-size-ust', dest='subbuffer_size_ust', type=int,
+            default=8*4096,
+            help='the size of the subbuffers for userspace events(default: 8*4096). '
+                 'buffer size must be power of two. '
+                 'available in iron or rolling only. ')
+        parser.add_argument(
+            '--subbuffer-size-kernel', dest='subbuffer_size_kernel', type=int,
+            default=32*4096,
+            help='the size of the subbuffers for kernel events(default: 32*4096). '
+                 'buffer size must be power of two. '
+                 'available in iron or rolling only. ')
 
     def main(self, *, args):
         if args.light_mode:
@@ -171,6 +183,23 @@ def main(self, *, args):
         else:
             init_args['context_fields'] = context_names
         init_args['display_list'] = args.list
+        # Note: keyword argument --subbuffer_size_ust/kernel are available in iron or rolling.
+
+        if os.environ['ROS_DISTRO'] not in ['iron', 'rolling'] \
+                and args.subbuffer_size_ust != 8*4096:
+            raise ValueError('the --subbuffer-size-ust option is '
+                             'available in iron or rolling')
+        if args.subbuffer_size_ust & (args.subbuffer_size_ust-1):
+            raise ValueError('--subbuffer-size-ust value must be power of two.')
+        init_args['subbuffer_size_ust'] = args.subbuffer_size_ust
+
+        if os.environ['ROS_DISTRO'] not in ['iron', 'rolling'] \
+                and args.subbuffer_size_kernel != 32*4096:
+            raise ValueError('the --subbuffer-size-kernel option is '
+                             'available in iron or rolling')
+        if args.subbuffer_size_kernel & (args.subbuffer_size_kernel-1):
+            raise ValueError('--subbuffer-size-kernel value must be power of two.')
+        init_args['subbuffer_size_kernel'] = args.subbuffer_size_kernel
         init(**init_args)
 
         def _run():