diff --git a/tests/utils/run-serverless.js b/tests/utils/run-serverless.js
index 08915582e..0bb4d72da 100644
--- a/tests/utils/run-serverless.js
+++ b/tests/utils/run-serverless.js
@@ -1,40 +1,74 @@
 // Runs complete serverless instance in preconfigured environment, limited
-// to predefined plugins and hook events
+// to predefined plugins and hook events.
+// Optionally serverless instance can be freshly required with specifc modules mocked
 
 'use strict';
 
 const { values } = require('lodash');
 const overrideCwd = require('process-utils/override-cwd');
 const overrideArgv = require('process-utils/override-argv');
-const Serverless = require('../../lib/Serverless');
 
-module.exports = ({ cwd, cliArgs, pluginConstructorsWhitelist, hookNamesWhitelist }) =>
+const resolveServerless = (modulesCacheStub, callback) => {
+  if (!modulesCacheStub) return callback(require('../../lib/Serverless'));
+  const originalCache = Object.assign({}, require.cache);
+  for (const key of Object.keys(require.cache)) delete require.cache[key];
+  Object.assign(require.cache, modulesCacheStub);
+  const restore = () => {
+    for (const key of Object.keys(require.cache)) delete require.cache[key];
+    Object.assign(require.cache, originalCache);
+  };
+  try {
+    return callback(require('../../lib/Serverless')).then(
+      result => {
+        restore();
+        return result;
+      },
+      error => {
+        restore();
+        throw error;
+      }
+    );
+  } catch (error) {
+    restore();
+    throw error;
+  }
+};
+
+module.exports = ({
+  cwd,
+  cliArgs,
+  pluginConstructorsWhitelist,
+  hookNamesWhitelist,
+  modulesCacheStub,
+}) =>
   overrideCwd(cwd, () =>
-    overrideArgv({ args: ['serverless', ...(cliArgs || [])] }, () => {
-      // Intialize serverless instances in preconfigured environement
-      const serverless = new Serverless();
-      const { pluginManager } = serverless;
-      return serverless.init().then(() => {
-        // Strip registered hooks, so only those intended are executed
-        const whitelistedPlugins = pluginManager.plugins.filter(plugin =>
-          pluginConstructorsWhitelist.some(Plugin => plugin instanceof Plugin)
-        );
-
-        const { hooks } = pluginManager;
-        for (const hookName of Object.keys(hooks)) {
-          if (!hookNamesWhitelist.includes(hookName)) {
-            delete hooks[hookName];
-            continue;
-          }
-          hooks[hookName] = hooks[hookName].filter(({ hook }) =>
-            whitelistedPlugins.some(whitelistedPlugin =>
-              values(whitelistedPlugin.hooks).includes(hook)
-            )
+    overrideArgv({ args: ['serverless', ...(cliArgs || [])] }, () =>
+      resolveServerless(modulesCacheStub, Serverless => {
+        // Intialize serverless instances in preconfigured environment
+        const serverless = new Serverless();
+        const { pluginManager } = serverless;
+        return serverless.init().then(() => {
+          // Strip registered hooks, so only those intended are executed
+          const whitelistedPlugins = pluginManager.plugins.filter(plugin =>
+            pluginConstructorsWhitelist.some(Plugin => plugin instanceof Plugin)
           );
-        }
 
-        // Run plugin manager hooks
-        return serverless.run();
-      });
-    })
+          const { hooks } = pluginManager;
+          for (const hookName of Object.keys(hooks)) {
+            if (!hookNamesWhitelist.includes(hookName)) {
+              delete hooks[hookName];
+              continue;
+            }
+            hooks[hookName] = hooks[hookName].filter(({ hook }) =>
+              whitelistedPlugins.some(whitelistedPlugin =>
+                values(whitelistedPlugin.hooks).includes(hook)
+              )
+            );
+          }
+
+          // Run plugin manager hooks
+          return serverless.run();
+        });
+      })
+    )
   );