diff --git a/src/server/token/MongoTokenDao.ts b/src/server/token/MongoTokenDao.ts
index 539f43a..66c3c96 100644
--- a/src/server/token/MongoTokenDao.ts
+++ b/src/server/token/MongoTokenDao.ts
@@ -33,6 +33,7 @@ import {
 import { DocumentId } from "../../document/Document";
 import { TokenId, TokenNamespace } from "./Token";
 import { UnknownTokenError } from "./UnknownTokenError";
+import { context } from "../../error/ContextError";
 
 
 /**
@@ -188,8 +189,14 @@ export class MongoTokenDao implements TokenDao
 
                     if ( !field[ ns ] )
                     {
-                        reject( new UnknownTokenError(
-                            `Unknown token namespace '${ns}' for document '${doc_id}`
+                        reject( context(
+                            new UnknownTokenError(
+                                `Unknown token namespace '${ns}' for document '${doc_id}`
+                            ),
+                            {
+                                doc_id: doc_id,
+                                ns:     ns,
+                            }
                         ) );
                         return;
                     }
@@ -227,9 +234,15 @@ export class MongoTokenDao implements TokenDao
 
         if ( !last )
         {
-            throw new UnknownTokenError(
-                `Failed to locate last token for namespace '${ns}'` +
-                    `on document '${doc_id}'`
+            throw context(
+                new UnknownTokenError(
+                    `Failed to locate last token for namespace '${ns}'` +
+                        `on document '${doc_id}'`
+                ),
+                {
+                    doc_id: doc_id,
+                    ns:     ns,
+                },
             );
         }
 
@@ -263,9 +276,16 @@ export class MongoTokenDao implements TokenDao
 
         if ( !reqtok )
         {
-            throw new UnknownTokenError(
-                `Missing data for requested token '${ns}.${token_id}'` +
-                    `for document '${doc_id}'`
+            throw context(
+                new UnknownTokenError(
+                    `Missing data for requested token '${ns}.${token_id}'` +
+                        `for document '${doc_id}'`
+                ),
+                {
+                    doc_id:   doc_id,
+                    ns:       ns,
+                    token_id: token_id,
+                },
             );
         }
 
diff --git a/test/server/token/MongoTokenDaoTest.ts b/test/server/token/MongoTokenDaoTest.ts
index 47b1368..8fe0dff 100644
--- a/test/server/token/MongoTokenDaoTest.ts
+++ b/test/server/token/MongoTokenDaoTest.ts
@@ -34,6 +34,7 @@ import {
 
 import { DocumentId } from "../../../src/document/Document";
 import { UnknownTokenError } from "../../../src/server/token/UnknownTokenError";
+import { hasContext } from "../../../src/error/ContextError";
 
 
 import { expect, use as chai_use } from 'chai';
@@ -130,7 +131,7 @@ describe( 'server.token.TokenDao', () =>
             data:      "",
         };
 
-        ( <[string, TokenId, TokenQueryResult, TokenData|null, any][]>[
+        ( <[string, TokenId, TokenQueryResult, TokenData|null, any, any][]>[
             [
                 'retrieves token by id',
                 <TokenId>'tok123',
@@ -152,6 +153,7 @@ describe( 'server.token.TokenDao', () =>
                     status: expected_status,
                 },
                 null,
+                null,
             ],
 
             [
@@ -173,6 +175,11 @@ describe( 'server.token.TokenDao', () =>
                 },
                 null,
                 `${ns}.tok123`,
+                {
+                    doc_id:   did,
+                    ns:       ns,
+                    token_id: 'tok123',
+                },
             ],
 
             [
@@ -183,6 +190,10 @@ describe( 'server.token.TokenDao', () =>
                 },
                 null,
                 ns,
+                {
+                    doc_id: did,
+                    ns:     ns,
+                },
             ],
 
             [
@@ -206,6 +217,7 @@ describe( 'server.token.TokenDao', () =>
                     status: expected_status,
                 },
                 null,
+                null,
             ],
 
             [
@@ -218,6 +230,10 @@ describe( 'server.token.TokenDao', () =>
                 },
                 null,
                 ns,
+                {
+                    doc_id: did,
+                    ns:     ns,
+                },
             ],
 
             [
@@ -228,8 +244,12 @@ describe( 'server.token.TokenDao', () =>
                 },
                 null,
                 ns,
+                {
+                    doc_id: did,
+                    ns:     ns,
+                },
             ],
-        ] ).forEach( ( [ label, tok_id, dbresult, expected, failure ] ) =>
+        ] ).forEach( ( [ label, tok_id, dbresult, expected, fmsg, fcontext ] ) =>
             it( label, () =>
             {
                 const coll: MongoCollection = {
@@ -244,14 +264,26 @@ describe( 'server.token.TokenDao', () =>
                 const result = new Sut( coll, field, () => <UnixTimestamp>0 )
                     .getToken( did, ns, tok_id );
 
-                return ( failure !== null )
+                return ( fmsg !== null )
                     ? Promise.all( [
                         expect( result ).to.eventually.be.rejectedWith(
-                            UnknownTokenError, failure
+                            UnknownTokenError, fmsg
                         ),
                         expect( result ).to.eventually.be.rejectedWith(
                             UnknownTokenError, ''+did
                         ),
+                        result.catch( e =>
+                        {
+                            if ( !hasContext( e ) )
+                            {
+                                // TS will soon have type assertions and
+                                // then this conditional and return can be
+                                // removed
+                                return expect.fail();
+                            }
+
+                            return expect( e.context ).to.deep.equal( fcontext );
+                        } ),
                     ] )
                     : expect( result ).to.eventually.deep.equal( expected );
             } )