diff --git a/Lib/idlelib/idle_test/test_codecontext.py b/Lib/idlelib/idle_test/test_codecontext.py
index 3f070da022384ec..13465d5c98c4872 100644
--- a/Lib/idlelib/idle_test/test_codecontext.py
+++ b/Lib/idlelib/idle_test/test_codecontext.py
@@ -60,6 +60,8 @@ def setUpClass(cls):
         frame = cls.frame = Frame(root)
         text = cls.text = Text(frame)
         text.insert('1.0', code_sample)
+        # Make the text longer than the visible height, so that it can scroll.
+        text.insert('end', '\n' * (int(text['height']) + 2))
         # Need to pack for creation of code context text widget.
         frame.pack(side='left', fill='both', expand=1)
         text.grid(row=1, column=1, sticky=NSEW)
diff --git a/Lib/idlelib/idle_test/test_sidebar.py b/Lib/idlelib/idle_test/test_sidebar.py
index 848f12a5d7c1850..6901413c416afda 100644
--- a/Lib/idlelib/idle_test/test_sidebar.py
+++ b/Lib/idlelib/idle_test/test_sidebar.py
@@ -317,6 +317,10 @@ def test_drag_selection_up(self):
         self.assertEqual(self.get_selection(), ('2.0', '5.0'))
 
     def test_scroll(self):
+        # Synchronized scrolling needs the geometry of mapped widgets.
+        self.root.deiconify()
+        self.addCleanup(self.root.withdraw)
+
         self.linenumber.show_sidebar()
         self.text.insert('1.0', 'line\n' * 100)
         self.root.update()
diff --git a/Lib/test/test_tkinter/test_text.py b/Lib/test/test_tkinter/test_text.py
index 27423006a7e71b8..c28f4e3f130d7af 100644
--- a/Lib/test/test_tkinter/test_text.py
+++ b/Lib/test/test_tkinter/test_text.py
@@ -774,10 +774,16 @@ def test_count(self):
         self.assertRaises(TclError, text.count, '1.0', 'end', 'spam')
         self.assertRaises(TclError, text.count, '1.0', 'end', '-lines')
 
-        self.assertIsInstance(text.count('1.3', '1.5', 'ypixels', return_ints=True), int)
-        self.assertIsInstance(text.count('1.3', '1.5', 'ypixels'), tuple)
-        self.assertIsInstance(text.count('1.3', '1.5', 'update', 'ypixels', return_ints=True), int)
-        self.assertIsInstance(text.count('1.3', '1.5', 'update', 'ypixels'), int)
+        # The ypixels counts depend on the widget geometry.
+        text.update()
+
+        # Indices on the same display line have zero vertical distance.
+        self.assertEqual(text.count('1.3', '1.5', 'ypixels', return_ints=True), 0)
+        self.assertIsNone(text.count('1.3', '1.5', 'ypixels'))
+        self.assertIsInstance(text.count('1.3', '2.5', 'ypixels', return_ints=True), int)
+        self.assertIsInstance(text.count('1.3', '2.5', 'ypixels'), tuple)
+        self.assertIsInstance(text.count('1.3', '2.5', 'update', 'ypixels', return_ints=True), int)
+        self.assertIsInstance(text.count('1.3', '2.5', 'update', 'ypixels'), int)
         self.assertEqual(text.count('1.3', '1.3', 'update', 'ypixels', return_ints=True), 0)
         self.assertEqual(text.count('1.3', '1.3', 'update', 'ypixels'), None)
         self.assertEqual(text.count('1.3', '1.5', 'update', 'indices', return_ints=True), 2)