diff --git a/gnocchi/resource_type.py b/gnocchi/resource_type.py
index e46206ff7..203fa53d1 100644
--- a/gnocchi/resource_type.py
+++ b/gnocchi/resource_type.py
@@ -141,9 +141,9 @@ def __init__(self, min_length, max_length, *args, **kwargs):
 
     meta_schema_ext = {
         voluptuous.Required('min_length', default=0):
-        voluptuous.All(int, voluptuous.Range(min=0, max=255)),
-        voluptuous.Required('max_length', default=255):
-        voluptuous.All(int, voluptuous.Range(min=1, max=255))
+        voluptuous.All(int, voluptuous.Range(min=0, max=256)),
+        voluptuous.Required('max_length', default=256):
+        voluptuous.All(int, voluptuous.Range(min=1, max=256))
     }
 
     @property
diff --git a/gnocchi/tests/functional/gabbits/resource-type.yaml b/gnocchi/tests/functional/gabbits/resource-type.yaml
index b8eb0b47a..719665fd4 100644
--- a/gnocchi/tests/functional/gabbits/resource-type.yaml
+++ b/gnocchi/tests/functional/gabbits/resource-type.yaml
@@ -146,7 +146,7 @@ tests:
               foobar:
                   type: string
                   required: False
-                  max_length: 255
+                  max_length: 256
                   min_length: 0
               uuid:
                   type: uuid
@@ -200,7 +200,7 @@ tests:
                   type: string
                   required: False
                   min_length: 0
-                  max_length: 255
+                  max_length: 256
               uuid:
                   type: uuid
                   required: True
diff --git a/releasenotes/notes/string-attribute-max-length-33e037494a0e318c.yaml b/releasenotes/notes/string-attribute-max-length-33e037494a0e318c.yaml
new file mode 100644
index 000000000..50a966b7e
--- /dev/null
+++ b/releasenotes/notes/string-attribute-max-length-33e037494a0e318c.yaml
@@ -0,0 +1,6 @@
+---
+features:
+  - |
+    The maximum allowed length for string-type resource attributes has been
+    increased from 255 to 256 characters. This allows creating attributes
+    that accept values up to 256 characters long e.g. Swift container names.