diff --git a/gtsam/discrete/DiscreteKey.h b/gtsam/discrete/DiscreteKey.h
index 297d5570d..ec76f5941 100644
--- a/gtsam/discrete/DiscreteKey.h
+++ b/gtsam/discrete/DiscreteKey.h
@@ -21,6 +21,7 @@
 #include <gtsam/global_includes.h>
 #include <gtsam/inference/Key.h>
 
+#include <boost/serialization/vector.hpp>
 #include <map>
 #include <string>
 #include <vector>
@@ -79,8 +80,36 @@ namespace gtsam {
       }
     }
 
+    bool equals(const DiscreteKeys& other, double tol = 0) const {
+      if (this->size() != other.size()) {
+        return false;
+      }
+
+      for (size_t i = 0; i < this->size(); i++) {
+        if (this->at(i).first != other.at(i).first ||
+            this->at(i).second != other.at(i).second) {
+          return false;
+        }
+      }
+      return true;
+    }
+
+    /** Serialization function */
+    friend class boost::serialization::access;
+    template <class ARCHIVE>
+    void serialize(ARCHIVE& ar, const unsigned int /*version*/) {
+      ar& boost::serialization::make_nvp(
+          "DiscreteKeys",
+          boost::serialization::base_object<std::vector<DiscreteKey>>(*this));
+    }
+
   }; // DiscreteKeys
 
   /// Create a list from two keys
   GTSAM_EXPORT DiscreteKeys operator&(const DiscreteKey& key1, const DiscreteKey& key2);
-}
+
+  // traits
+  template <>
+  struct traits<DiscreteKeys> : public Testable<DiscreteKeys> {};
+
+  }  // namespace gtsam
diff --git a/gtsam/discrete/tests/testDiscreteFactor.cpp b/gtsam/discrete/tests/testDiscreteFactor.cpp
index 8681cf7eb..db0491c9d 100644
--- a/gtsam/discrete/tests/testDiscreteFactor.cpp
+++ b/gtsam/discrete/tests/testDiscreteFactor.cpp
@@ -16,14 +16,29 @@
  *  @author Duy-Nguyen Ta
  */
 
-#include <gtsam/base/Testable.h>
-#include <gtsam/discrete/DiscreteFactor.h>
 #include <CppUnitLite/TestHarness.h>
+#include <gtsam/base/Testable.h>
+#include <gtsam/base/serializationTestHelpers.h>
+#include <gtsam/discrete/DiscreteFactor.h>
+
 #include <boost/assign/std/map.hpp>
 using namespace boost::assign;
 
 using namespace std;
 using namespace gtsam;
+using namespace gtsam::serializationTestHelpers;
+
+/* ************************************************************************* */
+TEST(DisreteKeys, Serialization) {
+  DiscreteKeys keys;
+  keys& DiscreteKey(0, 2);
+  keys& DiscreteKey(1, 3);
+  keys& DiscreteKey(2, 4);
+
+  EXPECT(equalsObj<DiscreteKeys>(keys));
+  EXPECT(equalsXML<DiscreteKeys>(keys));
+  EXPECT(equalsBinary<DiscreteKeys>(keys));
+}
 
 /* ************************************************************************* */
 int main() {
@@ -31,4 +46,3 @@ int main() {
   return TestRegistry::runAllTests(tr);
 }
 /* ************************************************************************* */
-