diff --git a/src/apps/common/confirm.py b/src/apps/common/confirm.py
index 42cf048825..6ab5032bfb 100644
--- a/src/apps/common/confirm.py
+++ b/src/apps/common/confirm.py
@@ -7,7 +7,7 @@ signal = loop.Signal()
 
 
 @unimport
-async def confirm(session_id, content=None, code=None, *args, **kwargs):
+async def confirm(session_id, content, code=None, *args, **kwargs):
     from trezor.ui.confirm import ConfirmDialog, CONFIRMED
     from trezor.messages.ButtonRequest import ButtonRequest
     from trezor.messages.ButtonRequestType import Other
@@ -24,7 +24,7 @@ async def confirm(session_id, content=None, code=None, *args, **kwargs):
 
 
 @unimport
-async def hold_to_confirm(session_id, content=None, code=None, *args, **kwargs):
+async def hold_to_confirm(session_id, content, code=None, *args, **kwargs):
     from trezor.ui.confirm import HoldToConfirmDialog, CONFIRMED
     from trezor.messages.ButtonRequest import ButtonRequest
     from trezor.messages.ButtonRequestType import Other
diff --git a/src/trezor/ui/confirm.py b/src/trezor/ui/confirm.py
index b54eb1a3ba..0827dcfc3f 100644
--- a/src/trezor/ui/confirm.py
+++ b/src/trezor/ui/confirm.py
@@ -12,7 +12,7 @@ CANCELLED = const(2)
 
 class ConfirmDialog(Widget):
 
-    def __init__(self, content=None, confirm='Confirm', cancel='Cancel'):
+    def __init__(self, content, confirm='Confirm', cancel='Cancel'):
         self.content = content
         if cancel is not None:
             self.confirm = Button((121, 240 - 48, 119, 48), confirm,