diff --git a/src/tmuxp/cli/_formatter.py b/src/tmuxp/cli/_formatter.py
index 2296c37b..50b652e6 100644
--- a/src/tmuxp/cli/_formatter.py
+++ b/src/tmuxp/cli/_formatter.py
@@ -83,7 +83,7 @@ class TmuxpHelpFormatter(argparse.RawDescriptionHelpFormatter):
     """
 
     # Theme for colorization, set by create_themed_formatter() or externally
-    _theme: HelpTheme | None = None
+    _tmuxp_theme: HelpTheme | None = None
 
     def _fill_text(self, text: str, width: int, indent: str) -> str:
         """Fill text, colorizing examples sections if theme is available.
@@ -110,7 +110,7 @@ class TmuxpHelpFormatter(argparse.RawDescriptionHelpFormatter):
         >>> formatter._fill_text("hello", 80, "")
         'hello'
         """
-        theme = getattr(self, "_theme", None)
+        theme = getattr(self, "_tmuxp_theme", None)
         if not text or theme is None:
             return super()._fill_text(text, width, indent)
 
@@ -347,7 +347,7 @@ def create_themed_formatter(
     >>> colors = Colors(ColorMode.ALWAYS)
     >>> formatter_cls = create_themed_formatter(colors)
     >>> formatter = formatter_cls("test")
-    >>> formatter._theme is not None
+    >>> formatter._tmuxp_theme is not None
     True
 
     With colors disabled:
@@ -355,7 +355,7 @@ def create_themed_formatter(
     >>> colors = Colors(ColorMode.NEVER)
     >>> formatter_cls = create_themed_formatter(colors)
     >>> formatter = formatter_cls("test")
-    >>> formatter._theme is None
+    >>> formatter._tmuxp_theme is None
     True
     """
     # Import here to avoid circular import at module load
@@ -372,6 +372,6 @@ def create_themed_formatter(
 
         def __init__(self, prog: str, **kwargs: t.Any) -> None:
             super().__init__(prog, **kwargs)
-            self._theme = theme
+            self._tmuxp_theme = theme
 
     return ThemedTmuxpHelpFormatter
diff --git a/tests/cli/test_formatter.py b/tests/cli/test_formatter.py
index 3f1ba378..49b37142 100644
--- a/tests/cli/test_formatter.py
+++ b/tests/cli/test_formatter.py
@@ -30,8 +30,8 @@ def test_create_themed_formatter_with_colors_enabled(
     formatter_cls = create_themed_formatter(colors)
     formatter = formatter_cls("test")
 
-    assert formatter._theme is not None
-    assert formatter._theme.prog != ""  # Has color codes
+    assert formatter._tmuxp_theme is not None
+    assert formatter._tmuxp_theme.prog != ""  # Has color codes
 
 
 def test_create_themed_formatter_with_colors_disabled() -> None:
@@ -40,7 +40,7 @@ def test_create_themed_formatter_with_colors_disabled() -> None:
     formatter_cls = create_themed_formatter(colors)
     formatter = formatter_cls("test")
 
-    assert formatter._theme is None
+    assert formatter._tmuxp_theme is None
 
 
 def test_create_themed_formatter_auto_mode_respects_no_color(
@@ -51,7 +51,7 @@ def test_create_themed_formatter_auto_mode_respects_no_color(
     formatter_cls = create_themed_formatter()
     formatter = formatter_cls("test")
 
-    assert formatter._theme is None
+    assert formatter._tmuxp_theme is None
 
 
 def test_create_themed_formatter_auto_mode_respects_force_color(
@@ -63,7 +63,7 @@ def test_create_themed_formatter_auto_mode_respects_force_color(
     formatter_cls = create_themed_formatter()
     formatter = formatter_cls("test")
 
-    assert formatter._theme is not None
+    assert formatter._tmuxp_theme is not None
 
 
 def test_fill_text_with_theme_colorizes_examples(