diff --git a/src/event/schemas.ts b/src/event/schemas.ts
index 27cfd11..9444a98 100644
--- a/src/event/schemas.ts
+++ b/src/event/schemas.ts
@@ -79,6 +79,7 @@ export const schemaV1 = {
     source: {
       format: "uri-reference",
       type: "string",
+      minLength: 1,
     },
   },
   type: "object",
diff --git a/test/integration/cloud_event_test.ts b/test/integration/cloud_event_test.ts
index 1c7ee42..6b624f0 100644
--- a/test/integration/cloud_event_test.ts
+++ b/test/integration/cloud_event_test.ts
@@ -209,4 +209,20 @@ describe("A 1.0 CloudEvent", () => {
     expect(obj.source).to.equal(source);
     expect(obj.specversion).to.equal(Version.V1);
   });
+
+  it("throws if the provded source is empty string", () => {
+    try {
+      new CloudEvent({
+        id: "0815",
+        specversion: "1.0",
+        type: "my.event.type",
+        source: "",
+      });
+    } catch (err) {
+      expect(err).to.be.instanceOf(TypeError);
+      expect(err.message).to.include("invalid payload");
+      expect(err.errors[0].dataPath).to.equal(".source");
+      expect(err.errors[0].keyword).to.equal("minLength");
+    }
+  });
 });