diff --git a/blocks.go b/blocks.go
index d5f4df7..ea4bf70 100644
--- a/blocks.go
+++ b/blocks.go
@@ -11,6 +11,8 @@ import (
 	u "gx/ipfs/QmZNVWh8LLjAavuQ2JXuFmuYH3C11xo988vSgp7UQrTRj1/go-ipfs-util"
 )
 
+var errWrongHash = errors.New("Data did not match given hash!")
+
 type Block interface {
 	Multihash() mh.Multihash
 	Data() []byte
@@ -37,7 +39,7 @@ func NewBlockWithHash(data []byte, h mh.Multihash) (*BasicBlock, error) {
 	if u.Debug {
 		chk := u.Hash(data)
 		if string(chk) != string(h) {
-			return nil, errors.New("Data did not match given hash!")
+			return nil, errWrongHash
 		}
 	}
 	return &BasicBlock{data: data, multihash: h}, nil
diff --git a/blocks_test.go b/blocks_test.go
index 1d7aa2e..6c218be 100644
--- a/blocks_test.go
+++ b/blocks_test.go
@@ -89,7 +89,7 @@ func TestManualHash(t *testing.T) {
 	u.Debug = true
 
 	block, err = NewBlockWithHash(data, hash)
-	if err == nil {
+	if err != errWrongHash {
 		t.Fatal(err)
 	}