diff --git a/lib/index.js b/lib/index.js
index 96956863..40bb0107 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -14,13 +14,15 @@ module.exports.__tests = {
 function inspect(root, targetFile, options) {
   if (!options) { options = {}; }
   var command = options.command || 'python';
+  var includeDevDeps = !!(options.dev || false);
   var baseargs = [];
 
   if (path.basename(targetFile) === 'Pipfile') {
     // Check that pipenv is available by running it.
     var pipenvCheckProc = subProcess.executeSync('pipenv', ['--version']);
     if (pipenvCheckProc.status !== 0) {
-      throw new Error('Failed to run `pipenv`; please make sure it is installed.');
+      throw new Error(
+        'Failed to run `pipenv`; please make sure it is installed.');
     }
     command = 'pipenv';
     baseargs = ['run', 'python'];
@@ -29,7 +31,14 @@ function inspect(root, targetFile, options) {
   return Promise.all([
     getMetaData(command, baseargs, root),
     getDependencies(
-      command, baseargs, root, targetFile, options.allowMissing, options.args),
+      command,
+      baseargs,
+      root,
+      targetFile,
+      options.allowMissing,
+      includeDevDeps,
+      options.args
+    ),
   ])
   .then(function (result) {
     return {
@@ -123,8 +132,15 @@ function dumpAllFilesInTempDir(tempDirName) {
   });
 }
 
-function getDependencies(command, baseargs, root, targetFile,
-                         allowMissing, args) {
+function getDependencies(
+  command,
+  baseargs,
+  root,
+  targetFile,
+  allowMissing,
+  includeDevDeps,
+  args
+) {
   var tempDirObj = tmp.dirSync({
     unsafeCleanup: true
   });
@@ -134,7 +150,14 @@ function getDependencies(command, baseargs, root, targetFile,
   return subProcess.execute(
     command,
     [].concat(baseargs,
-              buildArgs(targetFile, allowMissing, tempDirObj.name, args)),
+              buildArgs(
+                targetFile,
+                allowMissing,
+                tempDirObj.name,
+                includeDevDeps,
+                args
+              )
+    ),
     { cwd: root }
   )
   .then(function (output) {
@@ -157,12 +180,18 @@ function getDependencies(command, baseargs, root, targetFile,
   });
 }
 
-function buildArgs(targetFile, allowMissing, tempDirPath, extraArgs) {
-
+function buildArgs(
+  targetFile,
+  allowMissing,
+  tempDirPath,
+  includeDevDeps,
+  extraArgs
+) {
   var pathToRun = path.join(tempDirPath, 'pip_resolve.py');
   var args = [pathToRun];
   if (targetFile) { args.push(targetFile); }
   if (allowMissing) { args.push('--allow-missing'); }
+  if (includeDevDeps) { args.push('--dev-deps'); }
   if (extraArgs) { args = args.concat(extraArgs); }
   return args;
-}
\ No newline at end of file
+}
diff --git a/plug/pip_resolve.py b/plug/pip_resolve.py
index 0ff1b1fb..e36a6189 100644
--- a/plug/pip_resolve.py
+++ b/plug/pip_resolve.py
@@ -117,12 +117,15 @@ def matches_environment(requirement):
 def is_testable(requirement):
     return requirement.editable == False and requirement.vcs is None
 
-def get_requirements_list(requirements_file_path):
+def get_requirements_list(requirements_file_path, dev_deps=False):
     # TODO: refactor recognizing the dependency manager to a single place
     if os.path.basename(requirements_file_path) == 'Pipfile':
         with io.open(requirements_file_path, 'r', encoding='utf-8') as f:
             requirements_data = f.read()
-        req_list = list(pipfile.parse(requirements_data).get('packages', []))
+        parsed_reqs = pipfile.parse(requirements_data)
+        req_list = list(parsed_reqs.get('packages', []))
+        if dev_deps:
+            req_list.extend(parsed_reqs.get('dev-packages', []))
     else:
         # assume this is a requirements.txt formatted file
         # Note: requirements.txt files are unicode and can be in any encoding.
@@ -135,7 +138,9 @@ def get_requirements_list(requirements_file_path):
     required = [req.name.replace('_', '-') for req in req_list]
     return required
 
-def create_dependencies_tree_by_req_file_path(requirements_file_path, allow_missing=False):
+def create_dependencies_tree_by_req_file_path(requirements_file_path,
+                                              allow_missing=False,
+                                              dev_deps=False):
     # get all installed packages
     pkgs = get_installed_distributions(local_only=False, skip=[])
 
@@ -146,7 +151,7 @@ def create_dependencies_tree_by_req_file_path(requirements_file_path, allow_miss
     dist_tree = utils.construct_tree(dist_index)
 
     # create a list of dependencies from the dependencies file
-    required = get_requirements_list(requirements_file_path)
+    required = get_requirements_list(requirements_file_path, dev_deps=dev_deps)
     installed = [p for p in dist_index]
     packages = []
     for r in required:
@@ -172,10 +177,16 @@ def main():
         action="store_true",
         help="don't fail if some packages listed in the dependencies file " +
              "are not installed")
+    parser.add_argument("--dev-deps",
+        action="store_true",
+        help="resolve dev dependencies")
     args = parser.parse_args()
 
     create_dependencies_tree_by_req_file_path(
-        args.requirements, args.allow_missing)
+        args.requirements,
+        allow_missing=args.allow_missing,
+        dev_deps=args.dev_deps,
+    )
 
 if __name__ == '__main__':
     sys.exit(main())
diff --git a/test/inspect.test.js b/test/inspect.test.js
index edbb3d8c..fd5ba2db 100644
--- a/test/inspect.test.js
+++ b/test/inspect.test.js
@@ -636,6 +636,39 @@ test('inspect pipenv app with auto-created virtualenv', function (t) {
   });
 });
 
+test('inspect pipenv app dev dependencies', function (t) {
+  return Promise.resolve().then(function () {
+    chdirWorkspaces('pipenv-app');
+
+    var venvCreated = testUtils.ensureVirtualenv('pipenv-app');
+    t.teardown(testUtils.activateVirtualenv('pipenv-app'));
+    if (venvCreated) {
+      return testUtils.pipenvInstall();
+    }
+  })
+  .then(function () {
+    return plugin.inspect('.', 'Pipfile', {dev: true})
+  })
+  .then(function (result) {
+    var pkg = result.package;
+
+    t.test('package dependencies', function (t) {
+      Object.keys(pipenvAppExpectedDependencies).forEach(function (depName) {
+        t.match(
+          pkg.dependencies[depName],
+          pipenvAppExpectedDependencies[depName].data,
+          pipenvAppExpectedDependencies[depName].msg
+        );
+      });
+
+      t.match(pkg.dependencies.virtualenv, {name: 'virtualenv'});
+
+      t.end();
+    });
+
+    t.end();
+  });
+});
 
 function chdirWorkspaces(dir) {
   process.chdir(path.resolve(__dirname, 'workspaces', dir));
diff --git a/test/python-plugin.test.js b/test/python-plugin.test.js
index d9195af7..8bc5d0f4 100644
--- a/test/python-plugin.test.js
+++ b/test/python-plugin.test.js
@@ -2,7 +2,7 @@ var test = require('tap').test;
 var plugin = require('../lib').__tests;
 
 test('check build args with array', function (t) {
-  var result = plugin.buildArgs('requirements.txt', false, "../plug", [
+  var result = plugin.buildArgs('requirements.txt', false, "../plug", false, [
     '-argOne',
     '-argTwo',
   ]);
@@ -16,7 +16,7 @@ test('check build args with array', function (t) {
 });
 
 test('check build args with array & allowMissing', function (t) {
-  var result = plugin.buildArgs('requirements.txt', true, "../plug", [
+  var result = plugin.buildArgs('requirements.txt', true, "../plug", false, [
     '-argOne',
     '-argTwo',
   ]);
@@ -30,8 +30,39 @@ test('check build args with array & allowMissing', function (t) {
   t.end();
 });
 
+test('check build args with array & devDeps', function (t) {
+  var result = plugin.buildArgs('requirements.txt', false, "../plug", true, [
+    '-argOne',
+    '-argTwo',
+  ]);
+  t.match(result[0], /.*\/plug\/pip_resolve\.py/);
+  t.deepEqual(result.slice(1), [
+    'requirements.txt',
+    '--dev-deps',
+    '-argOne',
+    '-argTwo',
+  ]);
+  t.end();
+});
+
+test('check build args with array & allowMissing & devDeps', function (t) {
+  var result = plugin.buildArgs('requirements.txt', true, "../plug", true, [
+    '-argOne',
+    '-argTwo',
+  ]);
+  t.match(result[0], /.*\/plug\/pip_resolve\.py/);
+  t.deepEqual(result.slice(1), [
+    'requirements.txt',
+    '--allow-missing',
+    '--dev-deps',
+    '-argOne',
+    '-argTwo',
+  ]);
+  t.end();
+});
+
 test('check build args with string', function (t) {
-  var result = plugin.buildArgs('requirements.txt', false, "../plug", '-argOne -argTwo');
+  var result = plugin.buildArgs('requirements.txt', false, "../plug", false, '-argOne -argTwo');
   t.match(result[0], /.*\/plug\/pip_resolve\.py/);
   t.deepEqual(result.slice(1), [
     'requirements.txt',
@@ -41,7 +72,7 @@ test('check build args with string', function (t) {
 });
 
 test('check build args with string & allowMissing', function (t) {
-  var result = plugin.buildArgs('requirements.txt', true, "../plug", '-argOne -argTwo');
+  var result = plugin.buildArgs('requirements.txt', true, "../plug", false, '-argOne -argTwo');
   t.match(result[0], /.*\/plug\/pip_resolve\.py/);
   t.deepEqual(result.slice(1), [
     'requirements.txt',