diff --git a/addons/api/addon/serializers/credential-library.js b/addons/api/addon/serializers/credential-library.js
index 1d35eaa07..609f21671 100644
--- a/addons/api/addon/serializers/credential-library.js
+++ b/addons/api/addon/serializers/credential-library.js
@@ -68,21 +68,25 @@ export default class CredentialLibrarySerializer extends ApplicationSerializer {
    */
   handleCredentialMappingOverrides(serialized, isNew) {
     const { credential_type, credential_mapping_overrides } = serialized;
+
     if (Object.keys(credential_mapping_overrides).length === 0) {
       serialized.credential_mapping_overrides = null;
     }
-    // API expects to send null to fields if it is undefined or deleted
-    if (credential_mapping_overrides && !isNew) {
-      serialized.credential_mapping_overrides = options.mapping_overrides[
-        credential_type
-      ].reduce((obj, key) => {
-        if (credential_mapping_overrides[key]) {
-          obj[key] = credential_mapping_overrides[key];
-        } else {
-          obj[key] = null;
-        }
-        return obj;
-      }, {});
+
+    if (!credential_mapping_overrides || isNew || !credential_type) {
+      return;
     }
+
+    // API expects to send null to fields if it is undefined or deleted
+    serialized.credential_mapping_overrides = options.mapping_overrides[
+      credential_type
+    ].reduce((obj, key) => {
+      if (credential_mapping_overrides[key]) {
+        obj[key] = credential_mapping_overrides[key];
+      } else {
+        obj[key] = null;
+      }
+      return obj;
+    }, {});
   }
 }
diff --git a/addons/api/tests/unit/serializers/credential-library-test.js b/addons/api/tests/unit/serializers/credential-library-test.js
index 158c9584c..fcb635751 100644
--- a/addons/api/tests/unit/serializers/credential-library-test.js
+++ b/addons/api/tests/unit/serializers/credential-library-test.js
@@ -138,6 +138,45 @@ module('Unit | Serializer | credential library', function (hooks) {
     });
   });
 
+  test('it serializes credential library updates without credential_type', function (assert) {
+    const store = this.owner.lookup('service:store');
+    const serializer = store.serializerFor('credential-library');
+    store.push({
+      data: {
+        id: '1',
+        type: 'credential-library',
+        attributes: {
+          type: TYPE_CREDENTIAL_LIBRARY_VAULT_GENERIC,
+          name: 'Name',
+          description: 'Description',
+          path: '/vault/path',
+          http_method: 'GET',
+          version: 1,
+          credential_type: null,
+          credential_mapping_overrides: {},
+        },
+      },
+    });
+    const record = store.peekRecord('credential-library', '1');
+    const snapshot = record._createSnapshot();
+    const serializedRecord = serializer.serialize(snapshot);
+
+    assert.deepEqual(serializedRecord, {
+      type: TYPE_CREDENTIAL_LIBRARY_VAULT_GENERIC,
+      credential_store_id: null,
+      name: 'Name',
+      description: 'Description',
+      credential_type: null,
+      credential_mapping_overrides: null,
+      attributes: {
+        path: '/vault/path',
+        http_method: 'GET',
+        http_request_body: null,
+      },
+      version: 1,
+    });
+  });
+
   test('it does not serialize http_request_body unless http_method is set to POST', function (assert) {
     const store = this.owner.lookup('service:store');
     const record = store.createRecord('credential-library', {
diff --git a/ui/admin/tests/acceptance/credential-library/update-test.js b/ui/admin/tests/acceptance/credential-library/update-test.js
index bf80f3d9f..d7995cf65 100644
--- a/ui/admin/tests/acceptance/credential-library/update-test.js
+++ b/ui/admin/tests/acceptance/credential-library/update-test.js
@@ -460,4 +460,58 @@ module('Acceptance | credential-libraries | update', function (hooks) {
       selectors.FIELD_VAULT_PATH_VALUE,
     );
   });
+
+  test('can update a vault generic credential library without credential_type and save changes without error', async function (assert) {
+    setRunOptions({
+      rules: {
+        'color-contrast': {
+          // [ember-a11y-ignore]: axe rule "color-contrast" automatically ignored on 2026-07-07
+          enabled: false,
+        },
+      },
+    });
+
+    const credentialLibraryWithoutType = this.server.create(
+      'credential-library',
+      {
+        scope: instances.scopes.project,
+        credentialStore: instances.credentialStore,
+        type: TYPE_CREDENTIAL_LIBRARY_VAULT_GENERIC,
+        credential_type: null,
+        credentialMappingOverrides: null,
+      },
+    );
+
+    await visit(
+      `${urls.credentialLibraries}/${credentialLibraryWithoutType.id}`,
+    );
+
+    await click(commonSelectors.EDIT_BTN, 'Activate edit mode');
+    await fillIn(commonSelectors.FIELD_NAME, commonSelectors.FIELD_NAME_VALUE);
+    await fillIn(
+      commonSelectors.FIELD_DESCRIPTION,
+      commonSelectors.FIELD_DESCRIPTION_VALUE,
+    );
+    await fillIn(selectors.FIELD_VAULT_PATH, selectors.FIELD_VAULT_PATH_VALUE);
+
+    await click(commonSelectors.SAVE_BTN);
+
+    const credentialLibrary = this.server.schema.credentialLibraries.find(
+      credentialLibraryWithoutType.id,
+    );
+
+    assert.strictEqual(
+      credentialLibrary.name,
+      commonSelectors.FIELD_NAME_VALUE,
+    );
+    assert.strictEqual(
+      credentialLibrary.description,
+      commonSelectors.FIELD_DESCRIPTION_VALUE,
+    );
+    assert.strictEqual(
+      credentialLibrary.attributes.path,
+      selectors.FIELD_VAULT_PATH_VALUE,
+    );
+    assert.strictEqual(credentialLibrary.credentialType, null);
+  });
 });