diff --git a/lib/barzahlen_v2/error.rb b/lib/barzahlen_v2/error.rb
index <HASH>..<HASH> 100644
--- a/lib/barzahlen_v2/error.rb
+++ b/lib/barzahlen_v2/error.rb
@@ -19,12 +19,12 @@ module BarzahlenV2
     class SignatureError < StandardError
       attr_reader :error_message
 
-      def initialize(message)
+      def initialize(error_message)
         @error_message = error_message
       end
 
       def message
-        return error_message
+        return @error_message
       end
 
       alias_method :to_s, :message
diff --git a/spec/lib/error_spec.rb b/spec/lib/error_spec.rb
index <HASH>..<HASH> 100644
--- a/spec/lib/error_spec.rb
+++ b/spec/lib/error_spec.rb
@@ -34,8 +34,8 @@ module BarzahlenV2
       it "creates error message correctly" do
         exception = BarzahlenV2::Error::SignatureError.new("The self generated signature is not complying to the provided signature.")
 
-        expect(exception.message).to eq("One or all MissingArgument(s): 'slip_id'")
-        expect(exception.to_s).to eq("One or all MissingArgument(s): 'slip_id'")
+        expect(exception.message).to eq("The self generated signature is not complying to the provided signature.")
+        expect(exception.to_s).to eq("The self generated signature is not complying to the provided signature.")
       end
     end
Fixed an error bug which wasn't assigning variables correctly