diff --git a/packages/plugins/src/wizards/ln.ts b/packages/plugins/src/wizards/ln.ts
index 21924c2baa..0bf172882b 100644
--- a/packages/plugins/src/wizards/ln.ts
+++ b/packages/plugins/src/wizards/ln.ts
@@ -25,6 +25,7 @@ export function renderLNWizard(
     html`<wizard-textfield
       label="lnType"
       .maybeValue=${lnType}
+      readonly
       required
       helper="${get('ln.wizard.lnTypeHelper')}"
     ></wizard-textfield>`,
@@ -37,11 +38,13 @@ export function renderLNWizard(
     html`<wizard-textfield
       label="prefix"
       nullable
+      readonly
       .maybeValue=${prefix}
       helper="${get('ln.wizard.prefixHelper')}"
     ></wizard-textfield>`,
     html`<wizard-textfield
       label="lnClass"
+      readonly
       required
       .maybeValue=${lnClass}
       helper="${get('ln.wizard.lnClassHelper')}"
@@ -49,6 +52,7 @@ export function renderLNWizard(
     html`<wizard-textfield
       label="inst"
       .maybeValue=${inst}
+      readonly
       helper="${get('ln.wizard.instHelper')}"
     ></wizard-textfield>`,
   ];
diff --git a/packages/plugins/src/wizards/ln0.ts b/packages/plugins/src/wizards/ln0.ts
index d3ca8a45d7..ad06a7e1a6 100644
--- a/packages/plugins/src/wizards/ln0.ts
+++ b/packages/plugins/src/wizards/ln0.ts
@@ -24,6 +24,7 @@ export function renderLN0Wizard(
     html`<wizard-textfield
       label="lnType"
       .maybeValue=${lnType}
+      readonly
       required
       helper="${get('ln0.wizard.lnTypeHelper')}"
     ></wizard-textfield>`,
@@ -35,6 +36,7 @@ export function renderLN0Wizard(
     ></wizard-textfield>`,
     html`<wizard-textfield
       label="lnClass"
+      readonly
       required
       .maybeValue=${lnClass}
       helper="${get('ln0.wizard.lnClassHelper')}"
@@ -42,6 +44,7 @@ export function renderLN0Wizard(
     html`<wizard-textfield
       label="inst"
       .maybeValue=${inst}
+      readonly
       helper="${get('ln0.wizard.instHelper')}"
     ></wizard-textfield>`,
   ];
diff --git a/packages/plugins/test/unit/wizards/ln.test.ts b/packages/plugins/test/unit/wizards/ln.test.ts
index a752fec87e..784c7bec10 100644
--- a/packages/plugins/test/unit/wizards/ln.test.ts
+++ b/packages/plugins/test/unit/wizards/ln.test.ts
@@ -21,9 +21,11 @@ describe('ln wizards', () => {
     lnClass: 'LN-class',
     inst: '1',
   };
-  const requiredFields = [
+  const readonlyFields = [
     'lnType',
+    'prefix',
     'lnClass',
+    'inst'
   ];
 
   const ln = <Element>(
@@ -56,15 +58,13 @@ describe('ln wizards', () => {
     });
   });
 
-  requiredFields.forEach((field) => {
-    it(`is a required field ${field}`, async () => {
+  readonlyFields.forEach((field) => {
+    it(`is a readonly field ${field}`, async () => {
       const input = (<WizardInputElement[]>inputs).find(
         (textField) => textField.label === field
       ) as WizardTextField;
 
-      await setWizardTextFieldValue(input!, '');
-
-      expect(input.checkValidity()).to.be.false;
+      expect(input.readOnly).to.be.true;
     });
   });
 });
diff --git a/packages/plugins/test/unit/wizards/ln0.test.ts b/packages/plugins/test/unit/wizards/ln0.test.ts
index c3fb5c2daf..b5e605059c 100644
--- a/packages/plugins/test/unit/wizards/ln0.test.ts
+++ b/packages/plugins/test/unit/wizards/ln0.test.ts
@@ -20,9 +20,10 @@ describe('ln0 wizards', () => {
     lnClass: 'LN0-class',
     inst: '1',
   };
-  const requiredFields = [
+  const readonlyFields = [
     'lnType',
     'lnClass',
+    'inst'
   ];
 
   const ln = <Element>(
@@ -55,15 +56,13 @@ describe('ln0 wizards', () => {
     });
   });
 
-  requiredFields.forEach((field) => {
-    it(`is a required field ${field}`, async () => {
+  readonlyFields.forEach((field) => {
+    it(`is a readonly field ${field}`, async () => {
       const input = (<WizardInputElement[]>inputs).find(
         (textField) => textField.label === field
       ) as WizardTextField;
 
-      await setWizardTextFieldValue(input!, '');
-
-      expect(input.checkValidity()).to.be.false;
+      expect(input.readOnly).to.be.true;
     });
   });
 });