diff --git a/lib/xpm_ruby.rb b/lib/xpm_ruby.rb
index d18e371..c6555b0 100644
--- a/lib/xpm_ruby.rb
+++ b/lib/xpm_ruby.rb
@@ -11,6 +11,8 @@ class AccessTokenExpired < Unauthorized; end
 
   class Forbidden < Error; end
 
+  class AuthenticationUnsuccessful < Forbidden; end
+
   class NotAvailable < Error; end
 
   class ConnectionFailed < Error; end
diff --git a/lib/xpm_ruby/connection.rb b/lib/xpm_ruby/connection.rb
index e9a8c0c..0691ab6 100644
--- a/lib/xpm_ruby/connection.rb
+++ b/lib/xpm_ruby/connection.rb
@@ -81,6 +81,8 @@ def handle_response(response)
         end
       when 403 # this can happen with a bad xero_tenant_id
         detail = JSON.parse(response.body)["Detail"]
+        raise AuthenticationUnsuccessful.new(detail) if detail == "AuthenticationUnsuccessful"
+
         raise Forbidden.new(detail)
       when 500
         raise InternalServerError.new(response.reason_phrase)
diff --git a/lib/xpm_ruby/version.rb b/lib/xpm_ruby/version.rb
index 5a16376..a116001 100644
--- a/lib/xpm_ruby/version.rb
+++ b/lib/xpm_ruby/version.rb
@@ -1,3 +1,3 @@
 module XpmRuby
-  VERSION = "0.4.0".freeze
+  VERSION = "0.4.1".freeze
 end
diff --git a/spec/xpm_ruby/connection_spec.rb b/spec/xpm_ruby/connection_spec.rb
index 1f34dfc..aa09b1d 100644
--- a/spec/xpm_ruby/connection_spec.rb
+++ b/spec/xpm_ruby/connection_spec.rb
@@ -22,7 +22,28 @@ module XpmRuby
           VCR.use_cassette("xpm_ruby/connection/get/bad_tenant") do
             connection = Connection.new(access_token: access_token, xero_tenant_id: "bad_tenant")
 
-            expect { connection.get(endpoint: "staff.api/list") }.to raise_error(XpmRuby::Forbidden, /AuthenticationUnsuccessful/)
+            expect { connection.get(endpoint: "staff.api/list") }
+              .to raise_error(XpmRuby::AuthenticationUnsuccessful, /AuthenticationUnsuccessful/)
+          end
+        end
+      end
+
+      context "when XPM returns another forbidden detail" do
+        before(:each) do
+          response = instance_double(
+            Faraday::Response,
+            status: 403,
+            body: { Detail: "InsufficientPermissions" }.to_json
+          )
+          allow_any_instance_of(Faraday::Connection).to receive(:get).and_return(response)
+        end
+
+        it "raises the generic forbidden error" do
+          connection = Connection.new(access_token: access_token, xero_tenant_id: xero_tenant_id)
+
+          expect { connection.get(endpoint: "staff.api/list") }.to raise_error do |error|
+            expect(error.class).to eq(XpmRuby::Forbidden)
+            expect(error.message).to eq("InsufficientPermissions")
           end
         end
       end
@@ -113,7 +134,8 @@ module XpmRuby
           VCR.use_cassette("xpm_ruby/connection/post/bad_tenant") do
             connection = Connection.new(access_token: access_token, xero_tenant_id: "bad_tenant")
 
-            expect { connection.post(endpoint: "job.api/add", data: xml_string) }.to raise_error(XpmRuby::Forbidden, /AuthenticationUnsuccessful/)
+            expect { connection.post(endpoint: "job.api/add", data: xml_string) }
+              .to raise_error(XpmRuby::AuthenticationUnsuccessful, /AuthenticationUnsuccessful/)
           end
         end
       end
@@ -149,7 +171,8 @@ module XpmRuby
           VCR.use_cassette("xpm_ruby/connection/put/bad_tenant") do
             connection = Connection.new(access_token: access_token, xero_tenant_id: "bad_tenant")
 
-            expect { connection.put(endpoint: "job.api/update", data: xml_string) }.to raise_error(XpmRuby::Forbidden, /AuthenticationUnsuccessful/)
+            expect { connection.put(endpoint: "job.api/update", data: xml_string) }
+              .to raise_error(XpmRuby::AuthenticationUnsuccessful, /AuthenticationUnsuccessful/)
           end
         end
       end
@@ -181,7 +204,8 @@ module XpmRuby
           VCR.use_cassette("xpm_ruby/connection/delete/bad_tenant") do
             connection = Connection.new(access_token: access_token, xero_tenant_id: "bad_tenant")
 
-            expect { connection.delete(endpoint: "client.api/contact", id: contact_id) }.to raise_error(XpmRuby::Forbidden, /AuthenticationUnsuccessful/)
+            expect { connection.delete(endpoint: "client.api/contact", id: contact_id) }
+              .to raise_error(XpmRuby::AuthenticationUnsuccessful, /AuthenticationUnsuccessful/)
           end
         end
       end