diff --git a/db/migrate/20150801074555_create_pairwise_pseudonymous_identifiers.rb b/db/migrate/20150731123113_create_pairwise_pseudonymous_identifiers.rb
similarity index 88%
rename from db/migrate/20150801074555_create_pairwise_pseudonymous_identifiers.rb
rename to db/migrate/20150731123113_create_pairwise_pseudonymous_identifiers.rb
index 3b346dda0..0cceecafd 100644
--- a/db/migrate/20150801074555_create_pairwise_pseudonymous_identifiers.rb
+++ b/db/migrate/20150731123113_create_pairwise_pseudonymous_identifiers.rb
@@ -4,7 +4,7 @@ class CreatePairwisePseudonymousIdentifiers < ActiveRecord::Migration
       t.belongs_to :o_auth_application, index: true
       t.belongs_to :user, index: true
 
-      t.primary_key :guid, :string, limit: 32
+      t.string :guid, :string, limit: 32
       t.string :sector_identifier
     end
     add_foreign_key :ppid, :o_auth_applications
diff --git a/db/schema.rb b/db/schema.rb
index adff167f8..51bfa6262 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -465,6 +465,7 @@ ActiveRecord::Schema.define(version: 20150828132451) do
     t.integer "o_auth_application_id", limit: 4
     t.integer "user_id",               limit: 4
     t.string  "guid",                  limit: 32
+    t.string  "string",                limit: 32
     t.string  "sector_identifier",     limit: 255
   end