diff --git a/django/utils/encoding.py b/django/utils/encoding.py
index 7d33f58f1a..65bc1ad728 100644
--- a/django/utils/encoding.py
+++ b/django/utils/encoding.py
@@ -108,19 +108,8 @@ def force_bytes(s, encoding='utf-8', strings_only=False, errors='strict'):
         return s
     if isinstance(s, memoryview):
         return bytes(s)
-    if isinstance(s, Promise):
+    if isinstance(s, Promise) or not isinstance(s, str):
         return str(s).encode(encoding, errors)
-    if not isinstance(s, str):
-        try:
-            return str(s).encode(encoding)
-        except UnicodeEncodeError:
-            if isinstance(s, Exception):
-                # An Exception subclass containing non-ASCII data that doesn't
-                # know how to print itself properly. We shouldn't raise a
-                # further exception.
-                return b' '.join(force_bytes(arg, encoding, strings_only, errors)
-                                 for arg in s)
-            return str(s).encode(encoding, errors)
     else:
         return s.encode(encoding, errors)
 
diff --git a/tests/utils_tests/test_encoding.py b/tests/utils_tests/test_encoding.py
index b7ffd0afe7..c1e3323f15 100644
--- a/tests/utils_tests/test_encoding.py
+++ b/tests/utils_tests/test_encoding.py
@@ -42,8 +42,8 @@ class TestEncodingUtils(SimpleTestCase):
         """
         error_msg = "This is an exception, voilà"
         exc = ValueError(error_msg)
-        result = force_bytes(exc)
-        self.assertEqual(result, error_msg.encode('utf-8'))
+        self.assertEqual(force_bytes(exc), error_msg.encode('utf-8'))
+        self.assertEqual(force_bytes(exc, encoding='ascii', errors='ignore'), b'This is an exception, voil')
 
     def test_force_bytes_strings_only(self):
         today = datetime.date.today()