diff --git a/panel/layout/flex.py b/panel/layout/flex.py
index ef26d38eeb..b1f2e0515c 100644
--- a/panel/layout/flex.py
+++ b/panel/layout/flex.py
@@ -2,6 +2,8 @@
 
 import param
 
+from param.parameterized import iscoroutinefunction, resolve_ref
+
 from ..reactive import ReactiveHTML
 from .base import ListLike
 
@@ -60,13 +62,24 @@ class FlexBox(ListLike, ReactiveHTML):
     _template = (Path(__file__).parent / 'flexbox.html').read_text('utf-8')
 
     def __init__(self, *objects, **params):
+        from ..pane.base import panel
         if 'sizing_mode' not in params:
             direction = params.get('flex_direction', self.flex_direction)
             if direction.startswith('row'):
                 params['sizing_mode'] = 'stretch_width'
             else:
                 params['sizing_mode'] = 'stretch_height'
-        super().__init__(objects=list(objects), **params)
+        if objects:
+            if 'objects' in params:
+                raise ValueError("A %s's objects should be supplied either "
+                                 "as positional arguments or as a keyword, "
+                                 "not both." % type(self).__name__)
+            params['objects'] = [panel(pane) for pane in objects]
+        elif 'objects' in params:
+            objects = params['objects']
+            if not resolve_ref(objects) or iscoroutinefunction(objects):
+                params['objects'] = [panel(pane) for pane in objects]
+        super().__init__(**params)
 
     def select(self, selector=None):
         """
diff --git a/panel/tests/layout/test_base.py b/panel/tests/layout/test_base.py
index 455ab9c301..f4bfb6c60e 100644
--- a/panel/tests/layout/test_base.py
+++ b/panel/tests/layout/test_base.py
@@ -5,7 +5,7 @@
 
 from panel.chat import ChatInterface
 from panel.layout import (
-    Accordion, Card, Column, Row, Spacer, Tabs, WidgetBox,
+    Accordion, Card, Column, FlexBox, Row, Spacer, Tabs, WidgetBox,
 )
 from panel.layout.base import ListPanel, NamedListPanel
 from panel.pane import Bokeh, Markdown
@@ -569,7 +569,6 @@ def test_no_expand_fixed(panel, document, comm):
 
     assert model.sizing_mode == 'fixed'
 
-
 @pytest.mark.parametrize('scroll_param', ["auto_scroll_limit", "scroll", "scroll_button_threshold", "view_latest"])
 def test_column_scroll_params_sets_scroll(scroll_param, document, comm):
     if scroll_param not in ["auto_scroll_limit", "scroll_button_threshold"]:
@@ -580,9 +579,10 @@ def test_column_scroll_params_sets_scroll(scroll_param, document, comm):
     assert getattr(col, scroll_param)
     assert col.scroll
 
-def test_pass_objects_ref(document, comm):
+@pytest.mark.parametrize('layout', [Row, Column, FlexBox])
+def test_pass_objects_ref(document, comm, layout):
     multi_select = MultiSelect(options=['foo', 'bar', 'baz'], value=['bar', 'baz'])
-    col = Column(objects=multi_select)
+    col = layout(objects=multi_select)
     col.get_root(document, comm=comm)
 
     assert len(col.objects) == 2