diff --git a/eth/filters/api_test.go b/eth/filters/api_test.go
index 02229a7549..4c0371ab67 100644
--- a/eth/filters/api_test.go
+++ b/eth/filters/api_test.go
@@ -27,13 +27,15 @@ import (
 
 func TestUnmarshalJSONNewFilterArgs(t *testing.T) {
 	var (
-		fromBlock rpc.BlockNumber = 0x123435
-		toBlock   rpc.BlockNumber = 0xabcdef
-		address0                  = common.HexToAddress("70c87d191324e6712a591f304b4eedef6ad9bb9d")
-		address1                  = common.HexToAddress("9b2055d370f73ec7d8a03e965129118dc8f5bf83")
-		topic0                    = common.HexToHash("3ac225168df54212a25c1c01fd35bebfea408fdac2e31ddd6f80a4bbf9a5f1ca")
-		topic1                    = common.HexToHash("9084a792d2f8b16a62b882fd56f7860c07bf5fa91dd8a2ae7e809e5180fef0b3")
-		topic2                    = common.HexToHash("6ccae1c4af4152f460ff510e573399795dfab5dcf1fa60d1f33ac8fdc1e480ce")
+		fromBlock     rpc.BlockNumber = 0x123435
+		toBlock       rpc.BlockNumber = 0xabcdef
+		fromBlockHash                 = common.HexToHash("ac225168df54212a25c1c01fd35bebfea408fdac2e31ddd6f80a4bbf9a5f1ca3")
+		toBlockHash                   = common.HexToHash("084a792d2f8b16a62b882fd56f7860c07bf5fa91dd8a2ae7e809e5180fef0b39")
+		address0                      = common.HexToAddress("70c87d191324e6712a591f304b4eedef6ad9bb9d")
+		address1                      = common.HexToAddress("9b2055d370f73ec7d8a03e965129118dc8f5bf83")
+		topic0                        = common.HexToHash("3ac225168df54212a25c1c01fd35bebfea408fdac2e31ddd6f80a4bbf9a5f1ca")
+		topic1                        = common.HexToHash("9084a792d2f8b16a62b882fd56f7860c07bf5fa91dd8a2ae7e809e5180fef0b3")
+		topic2                        = common.HexToHash("6ccae1c4af4152f460ff510e573399795dfab5dcf1fa60d1f33ac8fdc1e480ce")
 	)
 
 	// default values
@@ -182,4 +184,17 @@ func TestUnmarshalJSONNewFilterArgs(t *testing.T) {
 	if len(test7.Topics[2]) != 0 {
 		t.Fatalf("expected 0 topics, got %d topics", len(test7.Topics[2]))
 	}
+
+	// from, to block hash
+	var test8 FilterCriteria
+	vector = fmt.Sprintf(`{"fromBlock":"%s","toBlock":"%s"}`, fromBlockHash.Hex(), toBlockHash.Hex())
+	if err := json.Unmarshal([]byte(vector), &test8); err != nil {
+		t.Fatal(err)
+	}
+	if *test8.FromBlockHash != fromBlockHash {
+		t.Fatalf("expected FromBlock %s, got %s", fromBlockHash.Hex(), test8.FromBlockHash.Hex())
+	}
+	if *test8.ToBlockHash != toBlockHash {
+		t.Fatalf("expected ToBlock %s, got %s", toBlockHash.Hex(), test8.ToBlockHash.Hex())
+	}
 }
diff --git a/rpc/types.go b/rpc/types.go
index e114fee9e2..d74c27eeee 100644
--- a/rpc/types.go
+++ b/rpc/types.go
@@ -177,7 +177,7 @@ func (bnh *BlockNumberOrHash) UnmarshalJSON(data []byte) error {
 
 // IsHash returns true iff the value is a block hash.
 func (bnh BlockNumberOrHash) IsHash() bool {
-	return bnh[0] == '"' && bnh[len(bnh)-1] == '"' && len(bnh) == 44
+	return bnh[0] == '"' && bnh[len(bnh)-1] == '"' && len(bnh) == 68
 }
 
 // Hash returns the hash value, or nil if the value is not a hash.