diff --git a/pkg/client/manifest_create.go b/pkg/client/manifest_create.go
index bfa9ee6ef0..81ffe3c03e 100644
--- a/pkg/client/manifest_create.go
+++ b/pkg/client/manifest_create.go
@@ -73,6 +73,9 @@ func parseOptsToIndexOptions(opts CreateManifestOptions) (idxOpts []imgutil.Inde
 			imgutil.WithInsecure(),
 		}
 	}
+	if opts.Format == "" {
+		opts.Format = types.OCIImageIndex
+	}
 	return []imgutil.IndexOption{
 		imgutil.WithMediaType(opts.Format),
 	}
diff --git a/pkg/client/manifest_create_test.go b/pkg/client/manifest_create_test.go
index d61530a0d1..d1f65bff4d 100644
--- a/pkg/client/manifest_create_test.go
+++ b/pkg/client/manifest_create_test.go
@@ -92,19 +92,38 @@ func testCreateManifest(t *testing.T, when spec.G, it spec.S) {
 							indexLocalPath = filepath.Join(tmpDir, imgutil.MakeFileSafeName(indexRepoName))
 						})
 
-						it("creates the index adding the manifest", func() {
-							err = subject.CreateManifest(
-								context.TODO(),
-								CreateManifestOptions{
-									IndexRepoName: indexRepoName,
-									RepoNames:     []string{"busybox:1.36-musl"},
-									Format:        types.OCIImageIndex,
-								},
-							)
-							h.AssertNil(t, err)
-							index := h.ReadIndexManifest(t, indexLocalPath)
-							h.AssertEq(t, len(index.Manifests), 1)
-							h.AssertEq(t, index.MediaType, types.OCIImageIndex)
+						when("no media type is provided", func() {
+							it("creates the index adding the manifest", func() {
+								err = subject.CreateManifest(
+									context.TODO(),
+									CreateManifestOptions{
+										IndexRepoName: indexRepoName,
+										RepoNames:     []string{"busybox:1.36-musl"},
+									},
+								)
+								h.AssertNil(t, err)
+								index := h.ReadIndexManifest(t, indexLocalPath)
+								h.AssertEq(t, len(index.Manifests), 1)
+								// By default uses OCI media-types
+								h.AssertEq(t, index.MediaType, types.OCIImageIndex)
+							})
+						})
+
+						when("media type is provided", func() {
+							it("creates the index adding the manifest", func() {
+								err = subject.CreateManifest(
+									context.TODO(),
+									CreateManifestOptions{
+										IndexRepoName: indexRepoName,
+										RepoNames:     []string{"busybox:1.36-musl"},
+										Format:        types.DockerManifestList,
+									},
+								)
+								h.AssertNil(t, err)
+								index := h.ReadIndexManifest(t, indexLocalPath)
+								h.AssertEq(t, len(index.Manifests), 1)
+								h.AssertEq(t, index.MediaType, types.DockerManifestList)
+							})
 						})
 					})
 				})
@@ -131,7 +150,6 @@ func testCreateManifest(t *testing.T, when spec.G, it spec.S) {
 								CreateManifestOptions{
 									IndexRepoName: indexRepoName,
 									RepoNames:     []string{"busybox:1.36-musl"},
-									Format:        types.OCIImageIndex,
 									Publish:       true,
 								},
 							)
diff --git a/pkg/index/index_factory_test.go b/pkg/index/index_factory_test.go
index d4bfe7191b..da3c791e46 100644
--- a/pkg/index/index_factory_test.go
+++ b/pkg/index/index_factory_test.go
@@ -109,7 +109,7 @@ func testIndexFactory(t *testing.T, when spec.G, it spec.S) {
 				indexRepoName = h.NewRandomIndexRepoName()
 			})
 
-			it("errors a message", func() {
+			it("errors with a message", func() {
 				_, err = indexFactory.LoadIndex(indexRepoName)
 				h.AssertError(t, err, fmt.Sprintf("Image: '%s' not found", indexRepoName))
 			})
@@ -137,7 +137,7 @@ func testIndexFactory(t *testing.T, when spec.G, it spec.S) {
 				indexRepoName = h.NewRandomIndexRepoName()
 			})
 
-			it("errors a message", func() {
+			it("errors with a message", func() {
 				_, err = indexFactory.FetchIndex(indexRepoName, imgutil.FromBaseIndex(indexRepoName))
 				h.AssertNotNil(t, err)
 			})