diff --git a/Assets/UniGLTF/Tests/UniGLTF/TextureTests.cs b/Assets/UniGLTF/Tests/UniGLTF/TextureTests.cs
index 938359013..d1165e6d9 100644
--- a/Assets/UniGLTF/Tests/UniGLTF/TextureTests.cs
+++ b/Assets/UniGLTF/Tests/UniGLTF/TextureTests.cs
@@ -50,5 +50,18 @@ namespace UniGLTF
             var (bytes, mime) = GltfTextureExporter.GetBytesWithMime(readonlyTexture);
             Assert.NotNull(bytes);
         }
+
+        [Test]
+        public void ExportMetallicSmoothnessOcclusion_Test()
+        {
+            var exporter = new TextureExporter();
+            var metallic = new Texture2D(4, 4, TextureFormat.ARGB32, false, true);
+            var occlusion = new Texture2D(4, 4, TextureFormat.ARGB32, false, true);
+
+            Assert.AreEqual(-1, exporter.ExportMetallicSmoothnessOcclusion(null, 0, null));
+            Assert.AreEqual(0, exporter.ExportMetallicSmoothnessOcclusion(null, 0, occlusion));
+            Assert.AreEqual(0, exporter.ExportMetallicSmoothnessOcclusion(metallic, 0, null));
+            Assert.AreEqual(0, exporter.ExportMetallicSmoothnessOcclusion(metallic, 0, occlusion));
+        }
     }
 }