diff --git a/common/hexutil/hexutil_test.go b/common/hexutil/hexutil_test.go
index 5c89fa8c9d..24dce185e7 100644
--- a/common/hexutil/hexutil_test.go
+++ b/common/hexutil/hexutil_test.go
@@ -141,7 +141,7 @@ var (
 	}
 
 	hexStringValidityTest = []hexValidityTest{
-		{"0x", false},
+		{"0x", true},
 		{"asdcc", false},
 		{"0x00000102", true},
 	}
@@ -213,9 +213,9 @@ func TestDecodeUint64(t *testing.T) {
 	}
 }
 
-func TestIsValidHexString(t *testing.T) {
+func TestHas0xPrefix(t *testing.T) {
 	for _, test := range hexStringValidityTest {
-		actual := IsValidHexString(test.input)
+		actual := Has0xPrefix(test.input)
 		if actual != test.want {
 			t.Errorf("input %s: value mismatch: got %t, want %t", test.input, actual, test.want)
 		}
diff --git a/rpc/types_test.go b/rpc/types_test.go
index deb761fe2c..5ace764f22 100644
--- a/rpc/types_test.go
+++ b/rpc/types_test.go
@@ -54,9 +54,9 @@ func TestBlockNumberJSONUnmarshal(t *testing.T) {
 		18: {``, true, BlockNumber(0)},
 		19: {`88439993`, false, BlockNumber(88439993)},
 		20: {`-1`, true, BlockNumber(0)},
-		21: {`MaxInt64`, true, BlockNumber(0)},
-		22: {`MinInt64`, true, BlockNumber(0)},
-		23: {`MaxUint64`, true, BlockNumber(0)},
+		21: {`9223372036854775807`, false, BlockNumber(9223372036854775807)},
+		22: {`-9223372036854775808`, true, BlockNumber(0)},
+		23: {`18446744073709551615`, true, BlockNumber(0)},
 	}
 
 	for i, test := range tests {