diff --git a/cropper/test/lib/CropSpecMetadataTest.scala b/cropper/test/lib/CropSpecMetadataTest.scala
new file mode 100644
index 0000000000..421bc31441
--- /dev/null
+++ b/cropper/test/lib/CropSpecMetadataTest.scala
@@ -0,0 +1,52 @@
+package lib
+
+import com.gu.mediaservice.model._
+import org.joda.time.DateTime
+import org.scalatest.funspec.AnyFunSpec
+import org.scalatest.matchers.should.Matchers
+
+class CropSpecMetadataTest extends AnyFunSpec with Matchers with CropSpecMetadata {
+
+  private val cropSpec = CropSpec(
+    uri = "/test",
+    bounds = Bounds(1, 2, 3, 4), aspectRatio = Some("16:9"), `type` = ExportType.default
+  )
+  private val crop = Crop(
+    id = Some("123"),
+    specification = cropSpec,
+    author = Some("Tony McCrae"),
+    date = Some(DateTime.now),
+    master = None,
+    assets = List.empty,
+  )
+  private val dimensions = Dimensions(640, 480)
+
+  describe("metadata for crop spec") {
+    it("should serialize crop spec to key value pairs") {
+      val metadata = metadataForCrop(crop, dimensions)
+
+      metadata("width") shouldBe "640"
+      metadata("height") shouldBe "480"
+      metadata.get("aspect-ratio") shouldBe Some("16:9")
+      metadata.get("author") shouldBe Some("Tony McCrae")
+    }
+
+    it("should handle empty optional fields") {
+      val withEmptyField = cropSpec.copy(aspectRatio = None)
+
+      val metadata = metadataForCrop(crop.copy(specification = withEmptyField, author = None), dimensions)
+
+      metadata.get("aspect-ratio") shouldBe None
+      metadata.get("author") shouldBe Some("None")  // TODO this does not look intentional!
+    }
+
+    it("should round trip metadata back to crop spec") {
+      val metadata = metadataForCrop(crop, dimensions)
+
+      val roundTripped = cropSpecFromMetadata(metadata)
+
+      roundTripped shouldBe Some(cropSpec)
+    }
+  }
+
+}