diff --git a/lib/skyfall/firehose/message.rb b/lib/skyfall/firehose/message.rb
index 39fc5f9..24a2b07 100644
--- a/lib/skyfall/firehose/message.rb
+++ b/lib/skyfall/firehose/message.rb
@@ -187,16 +187,18 @@ module Skyfall
 
       raise DecodeError.new("Invalid object type: #{type.inspect}") unless type.is_a?(Hash)
       raise DecodeError.new("Invalid object type: #{data.inspect}") unless data.is_a?(Hash)
+      raise DecodeError.new("Missing data: #{type.inspect}") unless type['op']
+      raise DecodeError.new("Invalid object type: #{type['op'].inspect}") unless type['op'].is_a?(Integer)
 
-      if data['error']
+      if type['op'] == -1 && data['error']
         raise SubscriptionError.new(data['error'], data['message'])
+      elsif type['op'] != 1
+        raise UnsupportedError.new("Unexpected version: #{type['op']}")
       end
 
-      raise DecodeError.new("Missing data: #{type.inspect}") unless type['op'] && type['t']
-      raise DecodeError.new("Invalid object type: #{type['op'].inspect}") unless type['op'].is_a?(Integer)
+      raise DecodeError.new("Missing data: #{type.inspect}") unless type['t']
       raise DecodeError.new("Invalid object type: #{type['t'].inspect}") unless type['t'].is_a?(String)
       raise DecodeError.new("Invalid message type: #{type['t'].inspect}") unless type['t'].start_with?('#')
-      raise UnsupportedError.new("Unsupported version: #{type['op']}") unless type['op'] == 1
 
       [type, data]
     end
diff --git a/spec/firehose/ex_invalid_message.rb b/spec/firehose/ex_invalid_message.rb
index 2e29e4b..fcee94f 100644
--- a/spec/firehose/ex_invalid_message.rb
+++ b/spec/firehose/ex_invalid_message.rb
@@ -69,7 +69,7 @@ shared_examples_for "invalid firehose message" do
     it "should raise an error if type object's op is not equal 1" do
       data[0]['op'] = 2
 
-      expect { build_message(cbor) }.to raise_error(Skyfall::UnsupportedError, /Unsupported version/)
+      expect { build_message(cbor) }.to raise_error(Skyfall::UnsupportedError, /Unexpected version/)
     end
   end
 end