diff --git a/chain/types/ethtypes/eth_types.go b/chain/types/ethtypes/eth_types.go
index eb0e12891..af27ec58c 100644
--- a/chain/types/ethtypes/eth_types.go
+++ b/chain/types/ethtypes/eth_types.go
@@ -39,18 +39,24 @@ func (e EthUint64) MarshalJSON() ([]byte, error) {
 	return json.Marshal(e.Hex())
 }
 
+// UnmarshalJSON should be able to parse two types of input:
+// 1. a JSON string containing a hex-encoded uint64 starting with 0x
+// 2. a valid string containing a uint64 in decimal
 func (e *EthUint64) UnmarshalJSON(b []byte) error {
 	var s string
-	if err := json.Unmarshal(b, &s); err != nil {
-		return err
+	if err := json.Unmarshal(b, &s); err == nil {
+		parsedInt, err := strconv.ParseUint(strings.Replace(s, "0x", "", -1), 16, 64)
+		if err != nil {
+			return err
+		}
+		eint := EthUint64(parsedInt)
+		*e = eint
+		return nil
+	} else if eint, err := strconv.ParseUint(string(b), 10, 64); err == nil {
+		*e = EthUint64(eint)
+		return nil
 	}
-	parsedInt, err := strconv.ParseUint(strings.Replace(s, "0x", "", -1), 16, 64)
-	if err != nil {
-		return err
-	}
-	eint := EthUint64(parsedInt)
-	*e = eint
-	return nil
+	return fmt.Errorf("cannot parse %s into EthUint64", string(b))
 }
 
 func EthUint64FromHex(s string) (EthUint64, error) {
diff --git a/chain/types/ethtypes/eth_types_test.go b/chain/types/ethtypes/eth_types_test.go
index 89c38ba29..b05557b07 100644
--- a/chain/types/ethtypes/eth_types_test.go
+++ b/chain/types/ethtypes/eth_types_test.go
@@ -36,13 +36,16 @@ func TestEthIntUnmarshalJSON(t *testing.T) {
 		{[]byte("\"0x0\""), EthUint64(0)},
 		{[]byte("\"0x41\""), EthUint64(65)},
 		{[]byte("\"0x400\""), EthUint64(1024)},
+		{[]byte("0"), EthUint64(0)},
+		{[]byte("100"), EthUint64(100)},
+		{[]byte("1024"), EthUint64(1024)},
 	}
 
 	for _, tc := range testcases {
 		var i EthUint64
 		err := i.UnmarshalJSON(tc.Input.([]byte))
 		require.Nil(t, err)
-		require.Equal(t, i, tc.Output)
+		require.Equal(t, tc.Output, i)
 	}
 }