diff --git a/Lib/test/test_webbrowser.py b/Lib/test/test_webbrowser.py
index 0820b9123125a3..735a6ae4ad3295 100644
--- a/Lib/test/test_webbrowser.py
+++ b/Lib/test/test_webbrowser.py
@@ -3,6 +3,8 @@
 import subprocess
 from unittest import mock
 from test import support
+from test.support import script_helper
+import textwrap
 
 
 URL = 'http://www.example.com'
@@ -265,6 +267,23 @@ def test_register_default(self):
     def test_register_preferred(self):
         self._check_registration(preferred=True)
 
+    def test_environment_variable_BROWSER_is_respected(self):
+        script_helper.assert_python_ok("-c", textwrap.dedent("""
+            import shutil, unittest
+            from test import support, test_webbrowser
+
+            def mock_which(path):
+                return True
+
+            class Test(test_webbrowser.ImportTest):
+
+                def setUp(self):
+                    super().setUp()
+                    support.patch(self, shutil, 'which', mock_which)
+
+            unittest.main()
+        """), BROWSER='test_browser')
+
 
 class ImportTest(unittest.TestCase):
     def test_register(self):
diff --git a/Lib/webbrowser.py b/Lib/webbrowser.py
index 2a5729b446f0cc..b9a37d9e19fdf4 100755
--- a/Lib/webbrowser.py
+++ b/Lib/webbrowser.py
@@ -86,7 +86,7 @@ def open_new_tab(url):
     return open(url, 2)
 
 
-def _synthesize(browser, update_tryorder=1):
+def _synthesize(browser, update_tryorder=True):
     """Attempt to synthesize a controller base on existing controllers.
 
     This is useful to create a controller when a user specifies a path to
@@ -113,7 +113,7 @@ def _synthesize(browser, update_tryorder=1):
         controller = copy.copy(controller)
         controller.name = browser
         controller.basename = os.path.basename(browser)
-        register(browser, None, controller, update_tryorder)
+        register(browser, None, instance=controller, preferred=update_tryorder)
         return [None, controller]
     return [None, None]
 
@@ -564,7 +564,7 @@ def register_standard_browsers():
         # and prepend to _tryorder
         for cmdline in userchoices:
             if cmdline != '':
-                cmd = _synthesize(cmdline, -1)
+                cmd = _synthesize(cmdline, update_tryorder=False)
                 if cmd[1] is None:
                     register(cmdline, None, GenericBrowser(cmdline), preferred=True)