diff --git a/components/partition_table/gen_esp32part.py b/components/partition_table/gen_esp32part.py
index 97e63ccf4b1..ade202fc1c1 100755
--- a/components/partition_table/gen_esp32part.py
+++ b/components/partition_table/gen_esp32part.py
@@ -20,6 +20,7 @@ import struct
 import sys
 
 import rich_click as click
+from esp_pylib.cli_options import OptionEatAll
 from esp_pylib.cli_types import AnyIntType
 from esp_pylib.logger import log
 
@@ -793,7 +794,16 @@ def run_gen(
     default=None,
     help='Require app partitions to be suitable for secure boot',
 )
-@click.option('--extra-partition-subtypes', multiple=True, help='Extra partition subtype entries')
+# Use OptionEatAll to keep argparse nargs='*' semantics: a single
+# --extra-partition-subtypes flag consumes all following space-separated
+# entries (CMake partition_table/CMakeLists.txt passes them this way).
+@click.option(
+    '--extra-partition-subtypes',
+    multiple=True,
+    cls=OptionEatAll,
+    type=str,
+    help='Extra partition subtype entries',
+)
 @click.argument('input_file', type=click.File('rb'), metavar='INPUT')
 @click.argument('output', type=click.Path(), required=False, default='-')
 def cli(
diff --git a/components/partition_table/parttool.py b/components/partition_table/parttool.py
index adf98a632b1..55a2f7ce7c5 100755
--- a/components/partition_table/parttool.py
+++ b/components/partition_table/parttool.py
@@ -270,7 +270,16 @@ def _partition_selection_options(func):
             help='select the default boot partition using the same fallback logic as the IDF bootloader',
         ),
         click.option('--partition-subtype', '-s', help='subtype of the partition'),
-        click.option('--extra-partition-subtypes', multiple=True, help='Extra partition subtype entries'),
+        # Use OptionEatAll to keep argparse nargs='*' semantics: a single
+        # --extra-partition-subtypes flag consumes all following space-separated
+        # entries (CMake project_include.cmake passes them this way).
+        click.option(
+            '--extra-partition-subtypes',
+            multiple=True,
+            cls=OptionEatAll,
+            type=str,
+            help='Extra partition subtype entries',
+        ),
     ]
     for decorator in reversed(decorators):
         func = decorator(func)