diff --git a/rpc/args_test.go b/rpc/args_test.go
index d6e4bee62c..bdf05cad14 100644
--- a/rpc/args_test.go
+++ b/rpc/args_test.go
@@ -74,6 +74,16 @@ func TestGetBlockByHashArgs(t *testing.T) {
 	}
 }
 
+func TestGetBlockByHashEmpty(t *testing.T) {
+	input := `[]`
+
+	args := new(GetBlockByHashArgs)
+	err := json.Unmarshal([]byte(input), &args)
+	if err == nil {
+		t.Error("Expected error but didn't get one")
+	}
+}
+
 func TestGetBlockByNumberArgs(t *testing.T) {
 	input := `["0x1b4", false]`
 	expected := new(GetBlockByNumberArgs)
@@ -94,6 +104,16 @@ func TestGetBlockByNumberArgs(t *testing.T) {
 	}
 }
 
+func TestGetBlockByNumberEmpty(t *testing.T) {
+	input := `[]`
+
+	args := new(GetBlockByNumberArgs)
+	err := json.Unmarshal([]byte(input), &args)
+	if err == nil {
+		t.Error("Expected error but didn't get one")
+	}
+}
+
 func TestNewTxArgs(t *testing.T) {
 	input := `[{"from": "0xb60e8dd61c5d32be8058bb8eb970870f07233155",
   "to": "0xd46e8dd67c5d32be8058bb8eb970870f072445675",
@@ -309,6 +329,33 @@ func TestFilterOptionsWords(t *testing.T) {
 	}
 }
 
+func TestFilterOptionsNums(t *testing.T) {
+	input := `[{
+  "fromBlock": 2,
+  "toBlock": 3
+  }]`
+
+	args := new(FilterOptions)
+	err := json.Unmarshal([]byte(input), &args)
+	switch err.(type) {
+	case *DecodeParamError:
+		break
+	default:
+		t.Errorf("Should have *DecodeParamError but instead have %T", err)
+	}
+
+}
+
+func TestFilterOptionsEmptyArgs(t *testing.T) {
+	input := `[]`
+
+	args := new(FilterOptions)
+	err := json.Unmarshal([]byte(input), &args)
+	if err == nil {
+		t.Error("Expected error but didn't get one")
+	}
+}
+
 func TestDbArgs(t *testing.T) {
 	input := `["0x74657374","0x6b6579","0x6d79537472696e67"]`
 	expected := new(DbArgs)