diff --git a/util/config/validators/test/test_validate_storage.py b/util/config/validators/test/test_validate_storage.py
index 2e271edf0..6ce1e4483 100644
--- a/util/config/validators/test/test_validate_storage.py
+++ b/util/config/validators/test/test_validate_storage.py
@@ -1,3 +1,4 @@
+import moto
 import pytest
 
 from util.config.validators import ConfigValidationException
@@ -16,3 +17,20 @@ def test_validate_storage(unvalidated_config, expected):
       validator.validate(unvalidated_config, None, None)
   else:
     validator.validate(unvalidated_config, None, None)
+
+def test_validate_s3_storage():
+  validator = StorageValidator()
+  with moto.mock_s3():
+    with pytest.raises(ConfigValidationException) as ipe:
+      validator.validate({
+        'DISTRIBUTED_STORAGE_CONFIG': {
+          'default': ('S3Storage', {
+            's3_access_key': 'invalid',
+            's3_secret_key': 'invalid',
+            's3_bucket': 'somebucket',
+            'storage_path': ''
+          }),
+        }
+      }, None, None)
+
+    assert ipe.value.message == 'Invalid storage configuration: default: S3ResponseError: 404 Not Found'
\ No newline at end of file
diff --git a/util/config/validators/validate_storage.py b/util/config/validators/validate_storage.py
index ca2f79ed5..b240d6094 100644
--- a/util/config/validators/validate_storage.py
+++ b/util/config/validators/validate_storage.py
@@ -26,7 +26,8 @@ class StorageValidator(BaseValidator):
         # Run setup on the driver if the read/write succeeded.
         driver.setup()
       except Exception as ex:
-        raise ConfigValidationException('Invalid storage configuration: %s: %s' % (name, str(ex)))
+        msg = str(ex).strip()
+        raise ConfigValidationException('Invalid storage configuration: %s: %s' % (name, msg))
 
 
 def _get_storage_providers(config):