diff --git a/src/lib/registration/ui/base_system_registration_dialog.rb b/src/lib/registration/ui/base_system_registration_dialog.rb
index da5fe6cfe..0aaa0885d 100644
--- a/src/lib/registration/ui/base_system_registration_dialog.rb
+++ b/src/lib/registration/ui/base_system_registration_dialog.rb
@@ -65,6 +65,9 @@ def run
           Yast::GetInstArgs.enable_next || Yast::Mode.normal
         )
 
+        # Limit the reg_code InputField to 512 (bsc#1098576)
+        Yast::UI.ChangeWidget(:reg_code, :InputMaxLength, 512)
+
         # Set default action
         self.action = initial_action
         set_focus
diff --git a/test/base_system_registration_dialog_test.rb b/test/base_system_registration_dialog_test.rb
index 7c28bfae9..0a7bb3755 100644
--- a/test/base_system_registration_dialog_test.rb
+++ b/test/base_system_registration_dialog_test.rb
@@ -32,6 +32,7 @@
       allow(Yast::Mode).to receive(:mode).and_return(mode)
       allow(Registration::Registration).to receive(:is_registered?).and_return(registered?)
       allow(Registration::UrlHelpers).to receive(:slp_discovery_feedback).and_return([])
+      allow(Yast::UI).to receive(:ChangeWidget)
     end
 
     context "when system is not registered" do
@@ -44,6 +45,14 @@
         allow(Registration::Helpers).to receive(:reset_registration_status)
       end
 
+      it "limits the reg_code InputField to 512" do
+        allow(subject).to receive(:event_loop).and_return(nil)
+
+        expect(Yast::UI).to receive(:ChangeWidget).with(:reg_code, :InputMaxLength, 512)
+
+        subject.run
+      end
+
       context "when user enters a correct regcode" do
         it "registers the base system with provided email and reg. code" do
           expect(Yast::UI).to receive(:QueryWidget).with(:email, :Value)