diff --git a/lib/vmfloaty/errors.rb b/lib/vmfloaty/errors.rb
new file mode 100644
index 0000000..b92211d
--- /dev/null
+++ b/lib/vmfloaty/errors.rb
@@ -0,0 +1,5 @@
+class AuthError < StandardError
+  def initialize(msg="Could not authenticate to pooler")
+    super
+  end
+end
diff --git a/lib/vmfloaty/pooler.rb b/lib/vmfloaty/pooler.rb
index c515d65..f633846 100644
--- a/lib/vmfloaty/pooler.rb
+++ b/lib/vmfloaty/pooler.rb
@@ -1,6 +1,7 @@
 require 'faraday'
 require 'vmfloaty/http'
 require 'json'
+require 'vmfloaty/errors'
 
 class Pooler
   def self.list(verbose, url, os_filter=nil)
@@ -40,10 +41,13 @@ class Pooler
     response = conn.post "vm/#{os_string}"
 
     res_body = JSON.parse(response.body)
+
     if res_body["ok"]
       res_body
+    elsif response.status == 401
+      raise AuthError, "HTTP #{response.status}: The token provided could not authenticate to the pooler.\n#{res_body}"
     else
-      raise "Failed to obtain VMs from the pooler at #{url}/vm/#{os_string}. #{res_body}"
+      raise "HTTP #{response.status}: Failed to obtain VMs from the pooler at #{url}/vm/#{os_string}. #{res_body}"
     end
   end
 
diff --git a/spec/vmfloaty/pooler_spec.rb b/spec/vmfloaty/pooler_spec.rb
index 881e883..697149e 100644
--- a/spec/vmfloaty/pooler_spec.rb
+++ b/spec/vmfloaty/pooler_spec.rb
@@ -44,6 +44,16 @@ describe Pooler do
       @retrieve_response_body_double = "{\"ok\":true,\"debian-7-i386\":{\"hostname\":[\"sc0o4xqtodlul5w\",\"4m4dkhqiufnjmxy\"]},\"centos-7-x86_64\":{\"hostname\":\"zb91y9qbrbf6d3q\"}}"
     end
 
+    it "raises an AuthError if the token is invalid" do
+      stub_request(:post, "#{@vmpooler_url}/vm/debian-7-i386").
+        with(:headers => {'Accept'=>'*/*', 'Accept-Encoding'=>'gzip;q=1.0,deflate;q=0.6,identity;q=0.3', 'Content-Length'=>'0', 'User-Agent'=>'Faraday v0.9.2', 'X-Auth-Token'=>'mytokenfile'}).
+        to_return(:status => 401, :body => "{\"ok\":false}", :headers => {})
+
+      vm_hash = {}
+      vm_hash['debian-7-i386'] = 1
+      expect{ Pooler.retrieve(false, vm_hash, 'mytokenfile', @vmpooler_url) }.to raise_error(AuthError)
+    end
+
     it "retrieves a single vm with a token" do
       stub_request(:post, "#{@vmpooler_url}/vm/debian-7-i386").
         with(:headers => {'Accept'=>'*/*', 'Accept-Encoding'=>'gzip;q=1.0,deflate;q=0.6,identity;q=0.3', 'Content-Length'=>'0', 'User-Agent'=>'Faraday v0.9.2', 'X-Auth-Token'=>'mytokenfile'}).