diff --git a/Lib/test/test_import.py b/Lib/test/test_import.py
index c17da10..e4d6523 100644
--- a/Lib/test/test_import.py
+++ b/Lib/test/test_import.py
@@ -397,6 +397,13 @@ class ImportTests(unittest.TestCase):
         finally:
             sys.path.pop(0)
 
+    def test_fromlist_error_messages(self):
+        # Test for issue #21720: fromlist unicode error messages
+        try:
+            __import__('encodings', fromlist=[u'aliases'])
+        except TypeError as exc:
+            self.assertIn("must be str, not unicode", str(exc))
+
 
 class PycRewritingTests(unittest.TestCase):
     # Test that the `co_filename` attribute on code objects always points
diff --git a/Python/import.c b/Python/import.c
index 92363b3..0053720 100644
--- a/Python/import.c
+++ b/Python/import.c
@@ -2566,6 +2566,12 @@ ensure_fromlist(PyObject *mod, PyObject *fromlist, char *buf, Py_ssize_t buflen,
             }
             return 0;
         }
+        if (PyUnicode_Check(item)) {
+            PyErr_SetString(PyExc_TypeError,
+                            "Item in ``from list'' must be str, not unicode");
+            Py_DECREF(item);
+            return 0;
+        }
         if (!PyString_Check(item)) {
             PyErr_SetString(PyExc_TypeError,
                             "Item in ``from list'' not a string");