diff --git a/lib/puppet/functions/archive/go_md5.rb b/lib/puppet/functions/archive/go_md5.rb
index 2dc8042..017e421 100644
--- a/lib/puppet/functions/archive/go_md5.rb
+++ b/lib/puppet/functions/archive/go_md5.rb
@@ -1,36 +1,36 @@
 require_relative '../../../puppet_x/bodeco/util.rb'
 
 # @summary
 #   Retrieves and returns specific file's md5 from GoCD server md5 checksum file
 # @api private
 # @see http://www.thoughtworks.com/products/docs/go/12.4/help/Artifacts_API.html
 Puppet::Functions.create_function(:'archive::go_md5') do
   # @param username
   #   GoCD username
   # @param password
   #   GoCD password
   # @param file
   #   GoCD filename
   # @param url
   #   The GoCD MD5 checkum URL
   # @return [String]
   #   The MD5 string
   dispatch :default_impl do
     param 'String', :username
     param 'String', :password
     param 'String[1]', :file
     param 'Stdlib::HTTPUrl', :url
     return_type 'String'
   end
 
   def default_impl(username, password, file, url)
     uri = URI(url)
     response = PuppetX::Bodeco::Util.content(uri, username: username, password: password)
 
     checksums = response.split("\n")
     line = checksums.find { |x| x =~ %r{#{file}=} }
-    md5 = line.match(%r{\b[0-9a-f]{5,40}\b})
-    raise("Could not parse md5 from url#{url} response: #{response.body}") unless md5
+    md5 = line.match(%r{\b[0-9a-f]{5,40}\b}) unless line.nil?
+    raise("Could not parse md5 from url #{url} response: #{response}") unless md5
     md5[0]
   end
 end
diff --git a/spec/functions/archive_go_md5_spec.rb b/spec/functions/archive_go_md5_spec.rb
index 3b007ac..d880bdb 100644
--- a/spec/functions/archive_go_md5_spec.rb
+++ b/spec/functions/archive_go_md5_spec.rb
@@ -1,16 +1,21 @@
 require 'spec_helper'
 
 describe 'archive::go_md5' do
-  let(:example_md5) do
-    File.read(fixtures('checksum', 'gocd.md5'))
-  end
+  let(:example_md5) { File.read(fixtures('checksum', 'gocd.md5')) }
+  let(:url) { 'https://gocd.lan/path/file.md5' }
+  let(:uri) { URI(url) }
 
   it { is_expected.not_to eq(nil) }
 
   it 'retreives file md5' do
-    url = 'https://gocd.lan/path/file.md5'
-    uri = URI(url)
     PuppetX::Bodeco::Util.stubs(:content).with(uri, username: 'user', password: 'pass').returns(example_md5)
     is_expected.to run.with_params('user', 'pass', 'filea', url).and_return('283158c7da8c0ada74502794fa8745eb')
   end
+
+  context 'when file doesn\'t exist' do
+    it 'raises error' do
+      PuppetX::Bodeco::Util.stubs(:content).with(uri, username: 'user', password: 'pass').returns(example_md5)
+      is_expected.to run.with_params('user', 'pass', 'non-existent-file', url).and_raise_error(RuntimeError, "Could not parse md5 from url https://gocd\.lan/path/file\.md5 response: #{example_md5}")
+    end
+  end
 end