diff --git a/Lib/unittest/loader.py b/Lib/unittest/loader.py
index ab36400..541884e 100644
--- a/Lib/unittest/loader.py
+++ b/Lib/unittest/loader.py
@@ -34,6 +34,11 @@
     TestClass = type(classname, (case.TestCase,), attrs)
     return suiteClass((TestClass(methodname),))
 
+def _jython_aware_splitext(path):
+    if path.lower().endswith('$py.class'):
+        return path[:-9]
+    return os.path.splitext(path)[0]
+
 
 class TestLoader(object):
     """
@@ -221,7 +226,7 @@
             return os.path.dirname(full_path)
 
     def _get_name_from_path(self, path):
-        path = os.path.splitext(os.path.normpath(path))[0]
+        path = _jython_aware_splitext(os.path.normpath(path))
 
         _relpath = os.path.relpath(path, self._top_level_dir)
         assert not os.path.isabs(_relpath), "Path must be within the project"
@@ -258,11 +263,11 @@
                     yield _make_failed_import_test(name, self.suiteClass)
                 else:
                     mod_file = os.path.abspath(getattr(module, '__file__', full_path))
-                    realpath = os.path.splitext(mod_file)[0]
-                    fullpath_noext = os.path.splitext(full_path)[0]
+                    realpath = _jython_aware_splitext(mod_file)
+                    fullpath_noext = _jython_aware_splitext(full_path)
                     if realpath.lower() != fullpath_noext.lower():
                         module_dir = os.path.dirname(realpath)
-                        mod_name = os.path.splitext(os.path.basename(full_path))[0]
+                        mod_name = _jython_aware_splitext(os.path.basename(full_path))
                         expected_dir = os.path.dirname(full_path)
                         msg = ("%r module incorrectly imported from %r. Expected %r. "
                                "Is this module globally installed?")
diff --git a/Misc/NEWS b/Misc/NEWS
index dab53d3..c07e555 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -24,6 +24,8 @@
 Library
 -------
 
+- Issue #10543: Fix unittest test discovery with Jython bytecode files.
+
 - Issue #1178863: Separate initialisation from setting when initializing
   Tkinter.Variables; harmonize exceptions to ValueError; only delete variables
   that have not been deleted; assert that variable names are strings.