diff --git a/Makefile b/Makefile
index 4cc3f79..5fb4a99 100644
--- a/Makefile
+++ b/Makefile
@@ -27,6 +27,9 @@ files:
 	git log --oneline --decorate --color > CHANGELOG
 
 test:
+	@install -d var
+	@echo "Looking up latest Amazon Linux AMI"
+	aws ec2 describe-images --owners amazon --filters 'Name=virtualization-type,Values=hvm' 'Name=root-device-type,Values=ebs' 'Name=architecture,Values=x86_64' 'Name=is-public,Values=true' 'Name=name,Values=amzn-ami-hvm-*-gp2' --query 'Images[*].{aws_source_ami:ImageId,created:CreationDate,description:Description}' |jq 'sort_by(.created)[-1]' |tee var/amazon-linux.json
 	pip install tox==1.7.1
 	tox
 
@@ -37,4 +40,4 @@ prepare:
 	python scripts/make-release.py
 
 publish:
-	python setup.py sdist upload
\ No newline at end of file
+	python setup.py sdist upload
diff --git a/packer.py b/packer.py
index a50758f..0a68826 100644
--- a/packer.py
+++ b/packer.py
@@ -115,7 +115,8 @@ def inspect(self, mrf=True):
 
         result = self.packer_cmd()
         if mrf:
-            result.parsed_output = self._parse_inspection_output(result.stdout)
+            result.parsed_output = self._parse_inspection_output(
+                result.stdout.decode('utf-8'))
         else:
             result.parsed_output = None
         return result
diff --git a/tester.py b/tester.py
index b537f08..ba60adb 100644
--- a/tester.py
+++ b/tester.py
@@ -7,14 +7,14 @@
 only = []
 # vars = {"variable1": "y", "variable2": "value"}
 vars = {}
-vars_file = '/x'
+var_file = 'packer/var/amazon-linux.json'
 
 p = packer.Installer('packer_executables/', 'packer_0.7.5_linux_amd64.zip')
 # If we installed packer using the provided installer, it will return
 # packer's executable path. We can use it below:
 # packer_exec = p.install()
 packer_exec = 'packer'
-p = packer.Packer(packerfile, exc=exc, only=only, vars=vars,
+p = packer.Packer(packerfile, exc=exc, only=only, vars=vars, var_file=var_file,
                   exec_path=packer_exec)
 # print(p.version())
 # validation = p.validate(syntax_only=True)
diff --git a/tests/resources/packerfile.json b/tests/resources/packerfile.json
index 36e6493..e83e79a 100644
--- a/tests/resources/packerfile.json
+++ b/tests/resources/packerfile.json
@@ -5,7 +5,7 @@
     "aws_access_key": "{{env `AWS_ACCESS_KEY_ID`}}",
     "aws_secret_key": "{{env `AWS_ACCESS_KEY`}}",
     "aws_source_ami": "",
-    "instance_type": "m3.large",
+    "instance_type": "t2.large",
     "virtualbox_source_image": "",
     "insecure_private_key": "./keys/insecure_private_key"
     },
@@ -80,4 +80,4 @@
       "format": "tar.gz"
     }
   ]
-}
\ No newline at end of file
+}
diff --git a/tests/test_packer.py b/tests/test_packer.py
index 424e01d..d327a8d 100644
--- a/tests/test_packer.py
+++ b/tests/test_packer.py
@@ -7,24 +7,25 @@
 TEST_RESOURCES_DIR = 'tests/resources'
 TEST_PACKERFILE = os.path.join(TEST_RESOURCES_DIR, 'packerfile.json')
 TEST_BAD_PACKERFILE = os.path.join(TEST_RESOURCES_DIR, 'badpackerfile.json')
+TEST_VARFILE = 'var/amazon-linux.json')
 
 
 class TestBase(testtools.TestCase):
 
     def test_build(self):
-        p = packer.Packer(TEST_PACKERFILE)
+        p = packer.Packer(TEST_PACKERFILE, var_file=TEST_VARFILE)
         p.build()
 
     def test_fix(self):
-        p = packer.Packer(TEST_PACKERFILE)
+        p = packer.Packer(TEST_PACKERFILE, var_file=TEST_VARFILE)
         p.fix()
 
     def test_inspect(self):
-        p = packer.Packer(TEST_PACKERFILE)
+        p = packer.Packer(TEST_PACKERFILE, var_file=TEST_VARFILE)
         p.inspect()
 
     def test_validate(self):
-        p = packer.Packer(TEST_PACKERFILE)
+        p = packer.Packer(TEST_PACKERFILE, var_file=TEST_VARFILE)
         p.validate()
 
     def test_version(self):