diff --git a/django/db/utils.py b/django/db/utils.py
index 5459fc9a33..485d908fb9 100644
--- a/django/db/utils.py
+++ b/django/db/utils.py
@@ -154,57 +154,38 @@ class ConnectionHandler(BaseConnectionHandler):
             )
         elif databases[DEFAULT_DB_ALIAS] == {}:
             databases[DEFAULT_DB_ALIAS]["ENGINE"] = "django.db.backends.dummy"
+
+        # Configure default settings.
+        for conn in databases.values():
+            conn.setdefault("ATOMIC_REQUESTS", False)
+            conn.setdefault("AUTOCOMMIT", True)
+            conn.setdefault("ENGINE", "django.db.backends.dummy")
+            if conn["ENGINE"] == "django.db.backends." or not conn["ENGINE"]:
+                conn["ENGINE"] = "django.db.backends.dummy"
+            conn.setdefault("CONN_MAX_AGE", 0)
+            conn.setdefault("CONN_HEALTH_CHECKS", False)
+            conn.setdefault("OPTIONS", {})
+            conn.setdefault("TIME_ZONE", None)
+            for setting in ["NAME", "USER", "PASSWORD", "HOST", "PORT"]:
+                conn.setdefault(setting, "")
+
+            test_settings = conn.setdefault("TEST", {})
+            default_test_settings = [
+                ("CHARSET", None),
+                ("COLLATION", None),
+                ("MIGRATE", True),
+                ("MIRROR", None),
+                ("NAME", None),
+            ]
+            for key, value in default_test_settings:
+                test_settings.setdefault(key, value)
         return databases
 
     @property
     def databases(self):
         return self.settings
 
-    def ensure_defaults(self, alias):
-        """
-        Put the defaults into the settings dictionary for a given connection
-        where no settings is provided.
-        """
-        try:
-            conn = self.settings[alias]
-        except KeyError:
-            raise self.exception_class(f"The connection '{alias}' doesn't exist.")
-
-        conn.setdefault("ATOMIC_REQUESTS", False)
-        conn.setdefault("AUTOCOMMIT", True)
-        conn.setdefault("ENGINE", "django.db.backends.dummy")
-        if conn["ENGINE"] == "django.db.backends." or not conn["ENGINE"]:
-            conn["ENGINE"] = "django.db.backends.dummy"
-        conn.setdefault("CONN_MAX_AGE", 0)
-        conn.setdefault("CONN_HEALTH_CHECKS", False)
-        conn.setdefault("OPTIONS", {})
-        conn.setdefault("TIME_ZONE", None)
-        for setting in ["NAME", "USER", "PASSWORD", "HOST", "PORT"]:
-            conn.setdefault(setting, "")
-
-    def prepare_test_settings(self, alias):
-        """
-        Make sure the test settings are available in the 'TEST' sub-dictionary.
-        """
-        try:
-            conn = self.settings[alias]
-        except KeyError:
-            raise self.exception_class(f"The connection '{alias}' doesn't exist.")
-
-        test_settings = conn.setdefault("TEST", {})
-        default_test_settings = [
-            ("CHARSET", None),
-            ("COLLATION", None),
-            ("MIGRATE", True),
-            ("MIRROR", None),
-            ("NAME", None),
-        ]
-        for key, value in default_test_settings:
-            test_settings.setdefault(key, value)
-
     def create_connection(self, alias):
-        self.ensure_defaults(alias)
-        self.prepare_test_settings(alias)
         db = self.settings[alias]
         backend = load_backend(db["ENGINE"])
         return backend.DatabaseWrapper(db, alias)
diff --git a/tests/db_utils/tests.py b/tests/db_utils/tests.py
index 99b58d0b8a..fe1d1e2d60 100644
--- a/tests/db_utils/tests.py
+++ b/tests/db_utils/tests.py
@@ -50,26 +50,6 @@ class ConnectionHandlerTests(SimpleTestCase):
         with self.assertRaisesMessage(ConnectionDoesNotExist, msg):
             conns["nonexistent"]
 
-    def test_ensure_defaults_nonexistent_alias(self):
-        msg = "The connection 'nonexistent' doesn't exist."
-        conns = ConnectionHandler(
-            {
-                DEFAULT_DB_ALIAS: {"ENGINE": "django.db.backends.dummy"},
-            }
-        )
-        with self.assertRaisesMessage(ConnectionDoesNotExist, msg):
-            conns.ensure_defaults("nonexistent")
-
-    def test_prepare_test_settings_nonexistent_alias(self):
-        msg = "The connection 'nonexistent' doesn't exist."
-        conns = ConnectionHandler(
-            {
-                DEFAULT_DB_ALIAS: {"ENGINE": "django.db.backends.dummy"},
-            }
-        )
-        with self.assertRaisesMessage(ConnectionDoesNotExist, msg):
-            conns.prepare_test_settings("nonexistent")
-
 
 class DatabaseErrorWrapperTests(TestCase):
     @unittest.skipUnless(connection.vendor == "postgresql", "PostgreSQL test")