diff --git a/server/api/middlewares/pagination.js b/server/api/middlewares/pagination.js
index 8c693ebc..456d7930 100644
--- a/server/api/middlewares/pagination.js
+++ b/server/api/middlewares/pagination.js
@@ -1,6 +1,6 @@
 // @flow
-import httpErrors from 'http-errors';
 import querystring from 'querystring';
+import { InvalidRequestError } from '../../errors';
 import { type Context } from 'koa';
 
 export default function pagination(options?: Object) {
@@ -24,7 +24,7 @@ export default function pagination(options?: Object) {
     offset = isNaN(offset) ? 0 : offset;
 
     if (limit > opts.maxLimit) {
-      throw httpErrors.BadRequest(
+      throw new InvalidRequestError(
         `Pagination limit is too large (max ${opts.maxLimit})`
       );
     }
diff --git a/server/emails/index.js b/server/emails/index.js
index 298941d5..175fc9fb 100644
--- a/server/emails/index.js
+++ b/server/emails/index.js
@@ -1,7 +1,7 @@
 // @flow
 import Koa from 'koa';
 import Router from 'koa-router';
-import httpErrors from 'http-errors';
+import { NotFoundError } from '../errors';
 import { Mailer } from '../mailer';
 
 const emailPreviews = new Koa();
@@ -22,7 +22,7 @@ router.get('/:type/:format', async ctx => {
       if (Object.getOwnPropertyNames(previewMailer).includes(ctx.params.type)) {
         // $FlowIssue flow doesn't like this but we're ok with it
         previewMailer[ctx.params.type]('user@example.com');
-      } else throw httpErrors.NotFound();
+      } else throw new NotFoundError('Email template could not be found');
   }
 
   if (!mailerOutput) return;
diff --git a/server/routes.js b/server/routes.js
index 4e578a01..c49c282d 100644
--- a/server/routes.js
+++ b/server/routes.js
@@ -2,7 +2,6 @@
 import React from 'react';
 import path from 'path';
 import fs from 'fs-extra';
-import httpErrors from 'http-errors';
 import Koa from 'koa';
 import Router from 'koa-router';
 import sendfile from 'koa-sendfile';
@@ -11,6 +10,7 @@ import subdomainRedirect from './middlewares/subdomainRedirect';
 import renderpage from './utils/renderpage';
 import { slackAuth } from '../shared/utils/routeHelpers';
 import { robotsResponse } from './utils/robots';
+import { NotFoundError } from './errors';
 
 import Home from './pages/Home';
 import About from './pages/About';
@@ -88,7 +88,7 @@ router.get('/robots.txt', ctx => (ctx.body = robotsResponse(ctx)));
 // catch all for react app
 router.get('*', async ctx => {
   await renderapp(ctx);
-  if (!ctx.status) ctx.throw(httpErrors.NotFound());
+  if (!ctx.status) ctx.throw(new NotFoundError());
 });
 
 // middleware
diff --git a/server/slack.js b/server/slack.js
index 098b6f5a..2d06d26a 100644
--- a/server/slack.js
+++ b/server/slack.js
@@ -1,14 +1,15 @@
 // @flow
 import fetch from 'isomorphic-fetch';
 import querystring from 'querystring';
-import httpErrors from 'http-errors';
+import { InvalidRequestError } from './errors';
 
 const SLACK_API_URL = 'https://slack.com/api';
 
 export async function post(endpoint: string, body: Object) {
   let data;
+
+  const token = body.token;
   try {
-    const token = body.token;
     const response = await fetch(`${SLACK_API_URL}/${endpoint}`, {
       method: 'POST',
       headers: {
@@ -18,10 +19,10 @@ export async function post(endpoint: string, body: Object) {
       body: JSON.stringify(body),
     });
     data = await response.json();
-  } catch (e) {
-    throw httpErrors.BadRequest();
+  } catch (err) {
+    throw new InvalidRequestError(err.message);
   }
-  if (!data.ok) throw httpErrors.BadRequest(data.error);
+  if (!data.ok) throw new InvalidRequestError(data.error);
 
   return data;
 }
@@ -33,10 +34,10 @@ export async function request(endpoint: string, body: Object) {
       `${SLACK_API_URL}/${endpoint}?${querystring.stringify(body)}`
     );
     data = await response.json();
-  } catch (e) {
-    throw httpErrors.BadRequest();
+  } catch (err) {
+    throw new InvalidRequestError(err.message);
   }
-  if (!data.ok) throw httpErrors.BadRequest(data.error);
+  if (!data.ok) throw new InvalidRequestError(data.error);
 
   return data;
 }