diff --git a/storages/backends/s3.py b/storages/backends/s3.py
index cf5dbe42..fdfc03d2 100644
--- a/storages/backends/s3.py
+++ b/storages/backends/s3.py
@@ -288,6 +288,8 @@ def __init__(self, **settings):
         super().__init__(**settings)
 
         check_location(self)
+        if not self.bucket_name:
+            raise ImproperlyConfigured("Setting a bucket name is required.")
 
         if (self.access_key or self.secret_key) and self.session_profile:
             raise ImproperlyConfigured(
diff --git a/tests/test_s3.py b/tests/test_s3.py
index 629ace61..d866d54b 100644
--- a/tests/test_s3.py
+++ b/tests/test_s3.py
@@ -956,6 +956,11 @@ def test_auth_config(self):
                 access_key="foo", secret_key="boo", session_profile="moo"
             )
 
+    def test_bucket_name_required(self):
+        with override_settings(AWS_STORAGE_BUCKET_NAME=None):
+            with self.assertRaises(ImproperlyConfigured):
+                s3.S3Storage()
+
 
 class S3StaticStorageTests(TestCase):
     def setUp(self):