diff --git a/README.md b/README.md
index 11e8ae5d..34878bf2 100644
--- a/README.md
+++ b/README.md
@@ -219,6 +219,9 @@ the following packages are omitted as they are already installed on Lambda:
  * s3transfer
  * setuptools
  * six
+ 
+Alternatively the `extendNoDeploy` option allows you to omit additional packages
+as well as those on teh default list.
 
 This example makes it instead omit pytest:
 ```yaml
@@ -228,6 +231,14 @@ custom:
       - pytest
 ```
 
+This example makes it omit numpy in addition to the above list:
+```yaml
+custom:
+  pythonRequirements:
+    extendNoDeploy:
+      - numpy
+```
+
 To include the default omitted packages, set the `noDeploy` option to an empty
 list:
 ```yaml
diff --git a/index.js b/index.js
index b5200285..f2950e7e 100644
--- a/index.js
+++ b/index.js
@@ -64,6 +64,7 @@ class ServerlessPythonRequirements {
           'pip',
           'setuptools'
         ],
+        extendNoDeploy: [],
         vendor: ''
       },
       (this.serverless.service.custom &&
@@ -104,6 +105,9 @@ class ServerlessPythonRequirements {
         options.layer = {};
       }
     }
+    if (options.extendNoDeploy.length > 0) {
+      options.noDeploy.push(...options.extendNoDeploy);
+    }
     return options;
   }
 
diff --git a/lib/inject.js b/lib/inject.js
index dc30be79..374a84b7 100644
--- a/lib/inject.js
+++ b/lib/inject.js
@@ -9,6 +9,45 @@ const { writeZip, zipFile } = require('./zipTree');
 
 BbPromise.promisifyAll(fse);
 
+/**
+ * Inject requirements into JSZip object
+ * @param {JSZip} zip js
+ * @param {string} requirementsPath requirements folder path
+ * @param {Object} options our options object
+ * @return {Promise} the JSZip object constructed.
+ */
+function injectRequirementsToZip(zip, requirementsPath, options) {
+  const noDeploy = new Set(options.noDeploy || []);
+  const runtimePath = 'python';
+
+  return BbPromise.resolve(
+    glob.sync([path.join(requirementsPath, '**')], {
+      mark: true,
+      dot: true
+    })
+  )
+    .map(file => [file, path.relative(requirementsPath, file)])
+    .filter(
+      ([file, relativeFile]) =>
+        !file.endsWith('/') &&
+        !relativeFile.match(/^__pycache__[\\/]/) &&
+        !noDeploy.has(relativeFile.split(/([-\\/]|\.py$|\.pyc$)/, 1)[0])
+    )
+    .map(([file, relativeFile]) =>
+      Promise.all([
+        file,
+        options.layer ? path.join(runtimePath, relativeFile) : relativeFile,
+        fse.statAsync(file)
+      ])
+    )
+    .map(([file, relativeFile, fileStat]) =>
+      zipFile(zip, relativeFile, fse.readFileAsync(file), {
+        unixPermissions: fileStat.mode
+      })
+    )
+    .then(() => zip);
+}
+
 /**
  * Inject requirements into packaged application.
  * @param {string} requirementsPath requirements folder path
@@ -17,35 +56,11 @@ BbPromise.promisifyAll(fse);
  * @return {Promise} the JSZip object constructed.
  */
 function injectRequirements(requirementsPath, packagePath, options) {
-  const noDeploy = new Set(options.noDeploy || []);
-
   return fse
     .readFileAsync(packagePath)
     .then(buffer => JSZip.loadAsync(buffer))
-    .then(zip =>
-      BbPromise.resolve(
-        glob.sync([path.join(requirementsPath, '**')], {
-          mark: true,
-          dot: true
-        })
-      )
-        .map(file => [file, path.relative(requirementsPath, file)])
-        .filter(
-          ([file, relativeFile]) =>
-            !file.endsWith('/') &&
-            !relativeFile.match(/^__pycache__[\\/]/) &&
-            !noDeploy.has(relativeFile.split(/([-\\/]|\.py$|\.pyc$)/, 1)[0])
-        )
-        .map(([file, relativeFile]) =>
-          Promise.all([file, relativeFile, fse.statAsync(file)])
-        )
-        .map(([file, relativeFile, fileStat]) =>
-          zipFile(zip, relativeFile, fse.readFileAsync(file), {
-            unixPermissions: fileStat.mode
-          })
-        )
-        .then(() => writeZip(zip, packagePath))
-    );
+    .then(zip => injectRequirementsToZip(zip, requirementsPath, options))
+    .then(zip => writeZip(zip, packagePath));
 }
 
 /**
@@ -130,4 +145,7 @@ function injectAllRequirements(funcArtifact) {
   }
 }
 
-module.exports = { injectAllRequirements };
+module.exports = {
+  injectAllRequirements,
+  injectRequirementsToZip
+};
diff --git a/lib/layer.js b/lib/layer.js
index 06c70871..19bc5e7c 100644
--- a/lib/layer.js
+++ b/lib/layer.js
@@ -2,7 +2,8 @@ const BbPromise = require('bluebird');
 const fse = require('fs-extra');
 const path = require('path');
 const JSZip = require('jszip');
-const { writeZip, addTree } = require('./zipTree');
+const { writeZip } = require('./zipTree');
+const { injectRequirementsToZip } = require('./inject');
 
 BbPromise.promisifyAll(fse);
 
@@ -13,10 +14,9 @@ BbPromise.promisifyAll(fse);
 function zipRequirements() {
   const rootZip = new JSZip();
   const src = path.join('.serverless', 'requirements');
-  const runtimepath = 'python';
 
-  return addTree(rootZip.folder(runtimepath), src).then(() =>
-    writeZip(rootZip, path.join('.serverless', 'pythonRequirements.zip'))
+  return injectRequirementsToZip(rootZip, src, this.options).then(zip =>
+    writeZip(zip, path.join('.serverless', 'pythonRequirements.zip'))
   );
 }