diff --git a/lib/permissions/minimally-encoded-raw-thread-info-validators.js b/lib/permissions/minimally-encoded-raw-thread-info-validators.js
--- a/lib/permissions/minimally-encoded-raw-thread-info-validators.js
+++ b/lib/permissions/minimally-encoded-raw-thread-info-validators.js
@@ -17,7 +17,6 @@
   type LegacyRawThreadInfo,
   legacyMemberInfoValidator,
   legacyRawThreadInfoValidator,
-  clientLegacyRoleInfoValidator,
   legacyThreadCurrentUserInfoValidator,
 } from '../types/thread-types.js';
 import { tBool, tID, tShape } from '../utils/validation-utils.js';
@@ -30,7 +29,8 @@
   });
 
 const roleInfoValidator: TInterface<RoleInfo> = tShape<RoleInfo>({
-  ...clientLegacyRoleInfoValidator.meta.props,
+  id: tID,
+  name: t.String,
   minimallyEncoded: tBool(true),
   permissions: t.list(tHexEncodedRolePermission),
   specialRole: t.maybe(specialRoleValidator),
diff --git a/lib/permissions/minimally-encoded-thread-permissions-test-data.js b/lib/permissions/minimally-encoded-thread-permissions-test-data.js
--- a/lib/permissions/minimally-encoded-thread-permissions-test-data.js
+++ b/lib/permissions/minimally-encoded-thread-permissions-test-data.js
@@ -352,7 +352,6 @@
         '015',
         '0a9',
       ],
-      isDefault: true,
       specialRole: specialRoles.DEFAULT_ROLE,
     },
   },
diff --git a/lib/permissions/minimally-encoded-thread-permissions.test.js b/lib/permissions/minimally-encoded-thread-permissions.test.js
--- a/lib/permissions/minimally-encoded-thread-permissions.test.js
+++ b/lib/permissions/minimally-encoded-thread-permissions.test.js
@@ -346,7 +346,6 @@
         id: 'roleID',
         name: 'roleName',
         permissions: ['abc', 'def'],
-        isDefault: true,
         specialRole: specialRoles.DEFAULT_ROLE,
       }),
     ).toBe(true);
diff --git a/lib/permissions/special-roles.test.js b/lib/permissions/special-roles.test.js
--- a/lib/permissions/special-roles.test.js
+++ b/lib/permissions/special-roles.test.js
@@ -16,7 +16,6 @@
       id: 'roleID',
       name: 'roleName',
       permissions: ['abc', 'def'],
-      isDefault: true,
       specialRole: specialRoles.DEFAULT_ROLE,
     };
     const patchedRole = patchRoleInfoWithSpecialRole(role);
@@ -29,7 +28,6 @@
       id: 'roleID',
       name: 'Admins',
       permissions: ['abc', 'def'],
-      isDefault: false,
       specialRole: specialRoles.ADMIN_ROLE,
     };
     const patchedRole = patchRoleInfoWithSpecialRole(role);
@@ -42,7 +40,6 @@
       id: 'roleID',
       name: 'BLAH',
       permissions: ['abc', 'def'],
-      isDefault: false,
       specialRole: null,
     };
     const patchedRole = patchRoleInfoWithSpecialRole(role);
@@ -84,7 +81,6 @@
         id: '256|83795',
         name: 'Members',
         permissions: ['000', '010', '005', '015', '0a7'],
-        isDefault: true,
         specialRole: specialRoles.DEFAULT_ROLE,
         minimallyEncoded: true,
       },
@@ -131,7 +127,6 @@
           '134',
           '156',
         ],
-        isDefault: false,
         specialRole: specialRoles.ADMIN_ROLE,
         minimallyEncoded: true,
       },
@@ -197,7 +192,6 @@
           '015',
           '0a9',
         ],
-        isDefault: false,
         specialRole: null,
         minimallyEncoded: true,
       },
diff --git a/lib/reducers/calendar-filters-reducer.test.js b/lib/reducers/calendar-filters-reducer.test.js
--- a/lib/reducers/calendar-filters-reducer.test.js
+++ b/lib/reducers/calendar-filters-reducer.test.js
@@ -49,7 +49,6 @@
           id: '256|83795',
           name: 'Members',
           permissions: ['000', '010', '005', '015', '0a7'],
-          isDefault: true,
           specialRole: specialRoles.DEFAULT_ROLE,
           minimallyEncoded: true,
         },
@@ -57,7 +56,6 @@
           id: '256|83796',
           name: 'Admins',
           permissions: ['000', '010', '005', '015', '0a7'],
-          isDefault: false,
           specialRole: specialRoles.ADMIN_ROLE,
           minimallyEncoded: true,
         },
@@ -108,7 +106,6 @@
           id: '256|83816',
           name: 'Members',
           permissions: ['000', '010', '005', '015', '0a7'],
-          isDefault: true,
           specialRole: specialRoles.DEFAULT_ROLE,
           minimallyEncoded: true,
         },
diff --git a/lib/shared/thread-utils.test.js b/lib/shared/thread-utils.test.js
--- a/lib/shared/thread-utils.test.js
+++ b/lib/shared/thread-utils.test.js
@@ -108,7 +108,6 @@
       id: '83795',
       name: 'Members',
       permissions: ['000', '010', '005', '015', '0a7'],
-      isDefault: true,
       specialRole: specialRoles.DEFAULT_ROLE,
       minimallyEncoded: true,
     },
@@ -155,7 +154,6 @@
         '134',
         '156',
       ],
-      isDefault: false,
       specialRole: specialRoles.ADMIN_ROLE,
       minimallyEncoded: true,
     },
diff --git a/lib/types/minimally-encoded-thread-permissions-types.js b/lib/types/minimally-encoded-thread-permissions-types.js
--- a/lib/types/minimally-encoded-thread-permissions-types.js
+++ b/lib/types/minimally-encoded-thread-permissions-types.js
@@ -4,6 +4,7 @@
 import _mapValues from 'lodash/fp/mapValues.js';
 
 import type { ClientAvatar } from './avatar-types.js';
+import type { ThreadRolePermissionsBlob } from './thread-permission-types.js';
 import type { ThreadType } from './thread-types-enum.js';
 import type {
   LegacyMemberInfo,
@@ -23,7 +24,9 @@
 import type { ThreadEntity } from '../utils/entity-text.js';
 
 export type RoleInfo = $ReadOnly<{
-  ...ClientLegacyRoleInfo,
+  +id: string,
+  +name: string,
+  +permissions: ThreadRolePermissionsBlob,
   +minimallyEncoded: true,
   +permissions: $ReadOnlyArray<string>,
   +specialRole: ?SpecialRole,
@@ -40,8 +43,9 @@
   } else if (roleIsAdminRole(roleInfo)) {
     specialRole = specialRoles.ADMIN_ROLE;
   }
+  const { isDefault, ...rest } = roleInfo;
   return {
-    ...roleInfo,
+    ...rest,
     minimallyEncoded: true,
     permissions: threadRolePermissionsBlobToBitmaskArray(roleInfo.permissions),
     specialRole,
@@ -57,6 +61,7 @@
     permissions: decodeThreadRolePermissionsBitmaskArray(
       minimallyEncodedRoleInfo.permissions,
     ),
+    isDefault: roleIsDefaultRole(minimallyEncodedRoleInfo),
   };
 };