diff --git a/beacon-chain/rpc/service.go b/beacon-chain/rpc/service.go
index d69fbb1a8..a44feed35 100644
--- a/beacon-chain/rpc/service.go
+++ b/beacon-chain/rpc/service.go
@@ -447,6 +447,9 @@ func assignmentsForPublicKeys(keys []*pb.PublicKey, beaconState *pbp2p.BeaconSta
 	assignments := []*pb.Assignment{}
 
 	for _, val := range keys {
+		if len(val.PublicKey) == 0 {
+			continue
+		}
 		// For the corresponding public key and current crystallized state,
 		// we determine the assigned slot for the validator and whether it
 		// should act as a proposer or attester.
diff --git a/beacon-chain/rpc/service_test.go b/beacon-chain/rpc/service_test.go
index 492728815..be946e831 100644
--- a/beacon-chain/rpc/service_test.go
+++ b/beacon-chain/rpc/service_test.go
@@ -656,3 +656,16 @@ func TestValidatorAssignments(t *testing.T) {
 	exitRoutine <- true
 	testutil.AssertLogsContain(t, hook, "Sending new cycle assignments to validator clients")
 }
+
+func TestAssignmentsForPublicKeys_emptyPubKey(t *testing.T) {
+	pks := []*pb.PublicKey{&pb.PublicKey{}}
+
+	a, err := assignmentsForPublicKeys(pks, nil)
+	if err != nil {
+		t.Error(err)
+	}
+
+	if len(a) > 0 {
+		t.Errorf("Expected no assignments, but got %v", a)
+	}
+}