diff --git a/lib/builder/builder.js b/lib/builder/builder.js
index 751a8a7e7b..55cb403eb6 100644
--- a/lib/builder/builder.js
+++ b/lib/builder/builder.js
@@ -324,6 +324,7 @@ export default class Builder extends Tapable {
       } else {
         // --- Production Build ---
         compiler.run((err, stats) => {
+          /* istanbul ignore if */
           if (err) {
             return reject(err)
           }
diff --git a/lib/core/nuxt.js b/lib/core/nuxt.js
index 6e4c8f534c..229a647dda 100644
--- a/lib/core/nuxt.js
+++ b/lib/core/nuxt.js
@@ -47,6 +47,7 @@ export default class Nuxt extends Tapable {
   listen (port = 3000, host = 'localhost') {
     return new Promise((resolve, reject) => {
       const server = this.renderer.app.listen({ port, host, exclusive: false }, err => {
+        /* istanbul ignore if */
         if (err) {
           return reject(err)
         }
@@ -61,6 +62,7 @@ export default class Nuxt extends Tapable {
           // Destroy server by forcing every connection to be closed
           server.destroy(err => {
             debug('server closed')
+            /* istanbul ignore if */
             if (err) {
               return reject(err)
             }
@@ -93,6 +95,7 @@ export default class Nuxt extends Tapable {
   async close (callback) {
     await this.applyPluginsAsync('close')
 
+    /* istanbul ignore if */
     if (typeof callback === 'function') {
       await callback()
     }
diff --git a/lib/core/renderer.js b/lib/core/renderer.js
index e147522629..b949391cce 100644
--- a/lib/core/renderer.js
+++ b/lib/core/renderer.js
@@ -132,6 +132,7 @@ export default class Renderer extends Tapable {
       basedir: this.options.rootDir
     }, this.options.render.ssr, this.options.build.ssr))
 
+    /* istanbul ignore if */
     if (this.options.build.ssr) {
       // eslint-disable-next-line no-console
       console.warn('[nuxt] `build.ssr` is deprecated and will be removed in 1.0 release, please use `renderer.ssr` instead!')
@@ -174,7 +175,8 @@ export default class Renderer extends Tapable {
       if (this.options.router.base !== '/' && req.url.indexOf(this.options.router.base) === 0) {
         req.url = req.url.replace(this.options.router.base, '/')
       }
-      // Prevent access to SSR resources
+      // Prevent access to SSR resources (TODO: write tests)
+      /* istanbul ignore if */
       if (ssrResourceRegex.test(req.url)) {
         res.statusCode = 404
         return res.end()