diff --git a/Lib/tkinter/test/test_tkinter/test_widgets.py b/Lib/tkinter/test/test_tkinter/test_widgets.py
index 05ef02e1c69035..7f95afdf05e5a8 100644
--- a/Lib/tkinter/test/test_tkinter/test_widgets.py
+++ b/Lib/tkinter/test/test_tkinter/test_widgets.py
@@ -936,7 +936,8 @@ def test_digits(self):
 
     def test_from(self):
         widget = self.create()
-        self.checkFloatParam(widget, 'from', 100, 14.9, 15.1, conv=float_round, allow_not_rounded=True)
+        # A change in Tk 8.6.10 means `from` is not rounded (bpo-41306)
+        self.checkFloatParam(widget, 'from', 100, 14.9, 15.1, conv=float_round if get_tk_patchlevel() < (8, 6, 10) else noconv)
 
     def test_label(self):
         widget = self.create()
diff --git a/Lib/tkinter/test/widget_tests.py b/Lib/tkinter/test/widget_tests.py
index bd54617d8b7911..b42ff52178f29e 100644
--- a/Lib/tkinter/test/widget_tests.py
+++ b/Lib/tkinter/test/widget_tests.py
@@ -101,15 +101,9 @@ def checkIntegerParam(self, widget, name, *values, **kwargs):
         self.checkInvalidParam(widget, name, 3.2,
                 errmsg='expected integer but got "3.2"')
 
-    def checkFloatParam(self, widget, name, *values, conv=float, allow_not_rounded=False, **kwargs):
+    def checkFloatParam(self, widget, name, *values, conv=float, **kwargs):
         for value in values:
-            try:
-                self.checkParam(widget, name, value, conv=conv, **kwargs)
-            except AssertionError:
-                if allow_not_rounded:
-                    self.checkParam(widget, name, value, conv=lambda val: val, **kwargs)
-                else:
-                    raise
+            self.checkParam(widget, name, value, conv=conv, **kwargs)
         self.checkInvalidParam(widget, name, '',
                 errmsg='expected floating-point number but got ""')
         self.checkInvalidParam(widget, name, 'spam',