diff --git a/poezio/windows/inputs.py b/poezio/windows/inputs.py
index b48fe318..6b0bc798 100644
--- a/poezio/windows/inputs.py
+++ b/poezio/windows/inputs.py
@@ -725,7 +725,7 @@ class CommandInput(HistoryInput):
         HistoryInput.__init__(self)
         self.on_abort = on_abort
         self.on_success = on_success
-        if on_input is None:
+        if on_input is not None:
             self.on_input = on_input
         else:
             self.on_input = DEFAULT_ON_INPUT
diff --git a/poezio/windows/text_win.py b/poezio/windows/text_win.py
index ef7e8f86..76c7d2d7 100644
--- a/poezio/windows/text_win.py
+++ b/poezio/windows/text_win.py
@@ -374,7 +374,7 @@ class TextWin(BaseTextWin):
             if get_theme().CHAR_TIME_RIGHT and message.str_time:
                 offset += 1
         lines = poopt.cut_text(txt, self.width - offset - 1)
-        prepend = default_color if default_color is None else ''
+        prepend = default_color if default_color else ''
         attrs = []  # type: List[str]
         for line in lines:
             saved = Line(
@@ -626,7 +626,7 @@ class XMLTextWin(BaseTextWin):
         if get_theme().CHAR_TIME_RIGHT and message.str_time:
             offset += 1
         lines = poopt.cut_text(txt, self.width - offset - 1)
-        prepend = default_color if default_color is not None else ''
+        prepend = default_color if default_color else ''
         attrs = []  # type: List[str]
         for line in lines:
             saved = Line(