diff --git a/addons/api/addon/models/storage-bucket.js b/addons/api/addon/models/storage-bucket.js
index 6f7d1b28e..8a1a4f1f7 100644
--- a/addons/api/addon/models/storage-bucket.js
+++ b/addons/api/addon/models/storage-bucket.js
@@ -38,7 +38,13 @@ export default class StorageBucketModel extends GeneratedStorageBucketModel {
    * @type {string}
    */
   get credentialType() {
-    if (!this.#credentialType) return 'static';
+    if (!this.#credentialType) {
+      if (this.role_arn) {
+        this.#credentialType = TYPE_CREDENTIAL_DYNAMIC;
+      } else {
+        this.#credentialType = TYPE_CREDENTIAL_STATIC;
+      }
+    }
     return this.#credentialType;
   }
 
diff --git a/addons/api/tests/unit/models/storage-bucket-test.js b/addons/api/tests/unit/models/storage-bucket-test.js
index 81ffa60e3..e88417da5 100644
--- a/addons/api/tests/unit/models/storage-bucket-test.js
+++ b/addons/api/tests/unit/models/storage-bucket-test.js
@@ -46,7 +46,7 @@ module('Unit | Model | storage bucket', function (hooks) {
   });
 
   test('it has credentialType property and returns the expected values', async function (assert) {
-    assert.expect(2);
+    assert.expect(4);
     const store = this.owner.lookup('service:store');
     const modelA = store.createRecord('storage-bucket', {
       role_arn: 'test-role-arn',
@@ -58,8 +58,18 @@ module('Unit | Model | storage bucket', function (hooks) {
       access_key_id: 'test-access-key-id',
       credentialType: TYPE_CREDENTIAL_STATIC,
     });
+    const modelC = store.createRecord('storage-bucket', {
+      role_arn: null,
+      access_key_id: 'test-access-key-id',
+    });
+    const modelD = store.createRecord('storage-bucket', {
+      role_arn: 'test-role-arn',
+      access_key_id: null,
+    });
     assert.strictEqual(modelA.credentialType, TYPE_CREDENTIAL_DYNAMIC);
     assert.strictEqual(modelB.credentialType, TYPE_CREDENTIAL_STATIC);
+    assert.strictEqual(modelC.credentialType, TYPE_CREDENTIAL_STATIC);
+    assert.strictEqual(modelD.credentialType, TYPE_CREDENTIAL_DYNAMIC);
   });
 
   test('it has isAWS property and returns the expected values', async function (assert) {