diff --git a/data/membership-schema/src/main/resources/net/corda/schema/membership/group/policy/1.0/corda.group.policy.json b/data/membership-schema/src/main/resources/net/corda/schema/membership/group/policy/1.0/corda.group.policy.json
index 3e7836316b..908f7217d4 100644
--- a/data/membership-schema/src/main/resources/net/corda/schema/membership/group/policy/1.0/corda.group.policy.json
+++ b/data/membership-schema/src/main/resources/net/corda/schema/membership/group/policy/1.0/corda.group.policy.json
@@ -267,7 +267,7 @@
                 "^ext\\.[a-zA-Z0-9.]+$": {
                   "description": "Optional. User-specified additional properties, which must be prefixed with `ext.`.",
                   "type": "string",
-                  "maxLength": 256
+                  "maxLength": 800
                 }
               },
               "properties": {
diff --git a/data/membership-schema/src/main/resources/net/corda/schema/membership/member/dynamic/registration/1.0/corda.member.dynamic.registration.json b/data/membership-schema/src/main/resources/net/corda/schema/membership/member/dynamic/registration/1.0/corda.member.dynamic.registration.json
index a199df440e..b54178bc4c 100644
--- a/data/membership-schema/src/main/resources/net/corda/schema/membership/member/dynamic/registration/1.0/corda.member.dynamic.registration.json
+++ b/data/membership-schema/src/main/resources/net/corda/schema/membership/member/dynamic/registration/1.0/corda.member.dynamic.registration.json
@@ -51,9 +51,9 @@
       "type": "string"
     },
     "^ext\\.[a-zA-Z0-9.]+$": {
-      "description": "Optional. A user can specify additional properties, they must be prefixed with `ext.`.",
+      "description": "Optional. User-specified additional properties, which must be prefixed with `ext.`.",
       "type": "string",
-      "maxLength": 256
+      "maxLength": 800
     }
   },
   "properties": {
diff --git a/data/membership-schema/src/main/resources/net/corda/schema/membership/member/static/registration/1.0/corda.member.static.registration.json b/data/membership-schema/src/main/resources/net/corda/schema/membership/member/static/registration/1.0/corda.member.static.registration.json
index 7876a43859..653613198b 100644
--- a/data/membership-schema/src/main/resources/net/corda/schema/membership/member/static/registration/1.0/corda.member.static.registration.json
+++ b/data/membership-schema/src/main/resources/net/corda/schema/membership/member/static/registration/1.0/corda.member.static.registration.json
@@ -21,7 +21,7 @@
     "^ext\\.[a-zA-Z0-9.]+$": {
       "description": "Optional. User-specified additional properties, which must be prefixed with `ext.`.",
       "type": "string",
-      "maxLength": 256
+      "maxLength": 800
     }
   },
   "properties": {
diff --git a/gradle.properties b/gradle.properties
index 3ddffb4960..da1b836127 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -9,7 +9,7 @@ cordaProductVersion = 5.1.0
 # NOTE: update this each time this module contains a breaking change
 ## NOTE: currently this is a top level revision, so all API versions will line up, but this could be moved to
 ##   a per module property in which case module versions can change independently.
-cordaApiRevision = 10
+cordaApiRevision = 11
 
 # Main
 kotlinVersion = 1.8.21