diff --git a/app/models/oauth2_user_info.rb b/app/models/oauth2_user_info.rb
index 69f35ed731c..285eb7a5c7a 100644
--- a/app/models/oauth2_user_info.rb
+++ b/app/models/oauth2_user_info.rb
@@ -21,5 +21,5 @@ end
 # Indexes
 #
 #  index_oauth2_user_infos_on_uid_and_provider      (uid,provider) UNIQUE
-#  index_oauth2_user_infos_on_user_id_and_provider  (user_id,provider) UNIQUE
+#  index_oauth2_user_infos_on_user_id_and_provider  (user_id,provider)
 #
diff --git a/db/migrate/20191022155215_add_index_to_oauth2_user_info.rb b/db/migrate/20191022155215_add_index_to_oauth2_user_info.rb
index dc9093a6c06..4c330ddae47 100644
--- a/db/migrate/20191022155215_add_index_to_oauth2_user_info.rb
+++ b/db/migrate/20191022155215_add_index_to_oauth2_user_info.rb
@@ -2,6 +2,6 @@
 
 class AddIndexToOauth2UserInfo < ActiveRecord::Migration[6.0]
   def change
-    add_index :oauth2_user_infos, [:user_id, :provider], unique: true
+    add_index :oauth2_user_infos, [:user_id, :provider]
   end
 end
diff --git a/db/migrate/20191025005204_amend_oauth2_user_info_index.rb b/db/migrate/20191025005204_amend_oauth2_user_info_index.rb
new file mode 100644
index 00000000000..15dcf001d31
--- /dev/null
+++ b/db/migrate/20191025005204_amend_oauth2_user_info_index.rb
@@ -0,0 +1,9 @@
+# frozen_string_literal: true
+
+class AmendOauth2UserInfoIndex < ActiveRecord::Migration[6.0]
+  def up
+    # remove old index which may have been unique
+    execute "DROP INDEX index_oauth2_user_infos_on_user_id_and_provider"
+    add_index :oauth2_user_infos, [:user_id, :provider]
+  end
+end