diff --git a/murmur.go b/murmur.go
index f99557c..1252cf7 100644
--- a/murmur.go
+++ b/murmur.go
@@ -3,8 +3,6 @@
 // license that can be found in the LICENSE file.
 
 /*
-Native (and fast) implementation of Austin Appleby's MurmurHash3.
-
 Package murmur3 implements Austin Appleby's non-cryptographic MurmurHash3.
 
  Reference implementation:
@@ -26,6 +24,7 @@ type digest struct {
 	clen int      // Digested input cumulative length.
 	tail []byte   // 0 to Size()-1 bytes view of `buf'.
 	buf  [16]byte // Expected (but not required) to be Size() large.
+	seed uint32   // Seed for initializing the hash.
 	bmixer
 }
 
diff --git a/murmur128.go b/murmur128.go
index 568eba7..a4b618b 100644
--- a/murmur128.go
+++ b/murmur128.go
@@ -18,6 +18,7 @@ var (
 	_ bmixer    = new(digest128)
 )
 
+// Hash128 represents a 128-bit hasher
 // Hack: the standard api doesn't define any Hash128 interface.
 type Hash128 interface {
 	hash.Hash
@@ -27,15 +28,17 @@ type Hash128 interface {
 // digest128 represents a partial evaluation of a 128 bites hash.
 type digest128 struct {
 	digest
-	seed uint64
-	h1   uint64 // Unfinalized running hash part 1.
-	h2   uint64 // Unfinalized running hash part 2.
+	h1 uint64 // Unfinalized running hash part 1.
+	h2 uint64 // Unfinalized running hash part 2.
 }
 
+// New128 returns a 128-bit hasher
 func New128() Hash128 { return New128WithSeed(0) }
 
+// New128WithSeed returns a 128-bit hasher set with explicit seed value
 func New128WithSeed(seed uint32) Hash128 {
-	d := &digest128{seed: uint64(seed)}
+	d := new(digest128)
+	d.seed = seed
 	d.bmixer = d
 	d.Reset()
 	return d
@@ -43,7 +46,7 @@ func New128WithSeed(seed uint32) Hash128 {
 
 func (d *digest128) Size() int { return 16 }
 
-func (d *digest128) reset() { d.h1, d.h2 = d.seed, d.seed }
+func (d *digest128) reset() { d.h1, d.h2 = uint64(d.seed), uint64(d.seed) }
 
 func (d *digest128) Sum(b []byte) []byte {
 	h1, h2 := d.Sum128()
@@ -186,8 +189,14 @@ func rotl64(x uint64, r byte) uint64 {
 //     return hasher.Sum128()
 func Sum128(data []byte) (h1 uint64, h2 uint64) { return Sum128WithSeed(data, 0) }
 
+// Sum128WithSeed returns the MurmurHash3 sum of data. It is equivalent to the
+// following sequence (without the extra burden and the extra allocation):
+//     hasher := New128WithSeed(seed)
+//     hasher.Write(data)
+//     return hasher.Sum128()
 func Sum128WithSeed(data []byte, seed uint32) (h1 uint64, h2 uint64) {
 	d := &digest128{h1: uint64(seed), h2: uint64(seed)}
+	d.seed = seed
 	d.tail = d.bmix(data)
 	d.clen = len(data)
 	return d.Sum128()
diff --git a/murmur32.go b/murmur32.go
index 7f687ea..6f9ed20 100644
--- a/murmur32.go
+++ b/murmur32.go
@@ -11,7 +11,6 @@ import (
 var (
 	_ hash.Hash   = new(digest32)
 	_ hash.Hash32 = new(digest32)
-	_ bmixer      = new(digest32)
 )
 
 const (
@@ -22,14 +21,16 @@ const (
 // digest32 represents a partial evaluation of a 32 bites hash.
 type digest32 struct {
 	digest
-	seed uint32
-	h1   uint32 // Unfinalized running hash.
+	h1 uint32 // Unfinalized running hash.
 }
 
+// New32 returns new 32-bit hasher
 func New32() hash.Hash32 { return New32WithSeed(0) }
 
+// New32WithSeed returns new 32-bit hasher set with explicit seed value
 func New32WithSeed(seed uint32) hash.Hash32 {
-	d := &digest32{seed: seed}
+	d := new(digest32)
+	d.seed = seed
 	d.bmixer = d
 	d.Reset()
 	return d
@@ -108,9 +109,14 @@ func rotl32(x uint32, r byte) uint32 {
 //     return hasher.Sum32()
 func Sum32(data []byte) uint32 { return Sum32WithSeed(data, 0) }
 
+// Sum32WithSeed returns the MurmurHash3 sum of data. It is equivalent to the
+// following sequence (without the extra burden and the extra allocation):
+//     hasher := New32WithSeed(seed)
+//     hasher.Write(data)
+//     return hasher.Sum32()
 func Sum32WithSeed(data []byte, seed uint32) uint32 {
 
-	var h1 uint32 = seed
+	h1 := seed
 
 	nblocks := len(data) / 4
 	var p uintptr
diff --git a/murmur64.go b/murmur64.go
index 85580d5..65a410a 100644
--- a/murmur64.go
+++ b/murmur64.go
@@ -14,8 +14,10 @@ var (
 // digest64 is half a digest128.
 type digest64 digest128
 
+// New64 returns a 64-bit hasher
 func New64() hash.Hash64 { return New64WithSeed(0) }
 
+// New64WithSeed returns a 64-bit hasher set with explicit seed value
 func New64WithSeed(seed uint32) hash.Hash64 {
 	d := (*digest64)(New128WithSeed(seed).(*digest128))
 	return d
@@ -40,8 +42,14 @@ func (d *digest64) Sum64() uint64 {
 //     return hasher.Sum64()
 func Sum64(data []byte) uint64 { return Sum64WithSeed(data, 0) }
 
+// Sum64WithSeed returns the MurmurHash3 sum of data. It is equivalent to the
+// following sequence (without the extra burden and the extra allocation):
+//     hasher := New64WithSeed(seed)
+//     hasher.Write(data)
+//     return hasher.Sum64()
 func Sum64WithSeed(data []byte, seed uint32) uint64 {
 	d := &digest128{h1: uint64(seed), h2: uint64(seed)}
+	d.seed = seed
 	d.tail = d.bmix(data)
 	d.clen = len(data)
 	h1, _ := d.Sum128()
diff --git a/murmur_test.go b/murmur_test.go
index 45367bd..fe564d0 100644
--- a/murmur_test.go
+++ b/murmur_test.go
@@ -2,7 +2,6 @@ package murmur3
 
 import (
 	"fmt"
-	"hash"
 	"testing"
 )
 
@@ -35,55 +34,56 @@ var data = []struct {
 func TestRefStrings(t *testing.T) {
 	for _, elem := range data {
 
-		var h32 hash.Hash32 = New32WithSeed(elem.seed)
+		h32 := New32WithSeed(elem.seed)
 		h32.Write([]byte(elem.s))
 		if v := h32.Sum32(); v != elem.h32 {
-			t.Errorf("'%s': 0x%x (want 0x%x)", elem.s, v, elem.h32)
+			t.Errorf("[Hash32] key: '%s', seed: '%d': 0x%x (want 0x%x)", elem.s, elem.seed, v, elem.h32)
 		}
 
 		h32.Reset()
 		h32.Write([]byte(elem.s))
 		target := fmt.Sprintf("%08x", elem.h32)
 		if p := fmt.Sprintf("%x", h32.Sum(nil)); p != target {
-			t.Errorf("'%s': %s (want %s)", elem.s, p, target)
+			t.Errorf("[Hash32] key: '%s', seed: '%d': %s (want %s)", elem.s, elem.seed, p, target)
 		}
 
 		if v := Sum32WithSeed([]byte(elem.s), elem.seed); v != elem.h32 {
-			t.Errorf("'%s': 0x%x (want 0x%x)", elem.s, v, elem.h32)
+			t.Errorf("[Hash32] key '%s', seed: '%d': 0x%x (want 0x%x)", elem.s, elem.seed, v, elem.h32)
 		}
 
-		var h64 hash.Hash64 = New64WithSeed(elem.seed)
+		h64 := New64WithSeed(elem.seed)
 		h64.Write([]byte(elem.s))
 		if v := h64.Sum64(); v != elem.h64_1 {
-			t.Errorf("'%s': 0x%x (want 0x%x)", elem.s, v, elem.h64_1)
+			t.Errorf("'[Hash64] key: '%s', seed: '%d': 0x%x (want 0x%x)", elem.s, elem.seed, v, elem.h64_1)
 		}
 
 		h64.Reset()
 		h64.Write([]byte(elem.s))
 		target = fmt.Sprintf("%016x", elem.h64_1)
 		if p := fmt.Sprintf("%x", h64.Sum(nil)); p != target {
-			t.Errorf("'%s': %s (want %s)", elem.s, p, target)
+			t.Errorf("[Hash64] key: '%s', seed: '%d': %s (want %s)", elem.s, elem.seed, p, target)
 		}
 
 		if v := Sum64WithSeed([]byte(elem.s), elem.seed); v != elem.h64_1 {
-			t.Errorf("'%s': 0x%x (want 0x%x)", elem.s, v, elem.h64_1)
+			t.Errorf("[Hash64] key: '%s', seed: '%d': 0x%x (want 0x%x)", elem.s, elem.seed, v, elem.h64_1)
 		}
 
-		var h128 Hash128 = New128WithSeed(elem.seed)
+		h128 := New128WithSeed(elem.seed)
+
 		h128.Write([]byte(elem.s))
 		if v1, v2 := h128.Sum128(); v1 != elem.h64_1 || v2 != elem.h64_2 {
-			t.Errorf("'%s': 0x%x-0x%x (want 0x%x-0x%x)", elem.s, v1, v2, elem.h64_1, elem.h64_2)
+			t.Errorf("[Hash128] key: '%s', seed: '%d': 0x%x-0x%x (want 0x%x-0x%x)", elem.s, elem.seed, v1, v2, elem.h64_1, elem.h64_2)
 		}
 
 		h128.Reset()
 		h128.Write([]byte(elem.s))
 		target = fmt.Sprintf("%016x%016x", elem.h64_1, elem.h64_2)
 		if p := fmt.Sprintf("%x", h128.Sum(nil)); p != target {
-			t.Errorf("'%s': %s (want %s)", elem.s, p, target)
+			t.Errorf("[Hash128] key: '%s', seed: '%d': %s (want %s)", elem.s, elem.seed, p, target)
 		}
 
 		if v1, v2 := Sum128WithSeed([]byte(elem.s), elem.seed); v1 != elem.h64_1 || v2 != elem.h64_2 {
-			t.Errorf("'%s': 0x%x-0x%x (want 0x%x-0x%x)", elem.s, v1, v2, elem.h64_1, elem.h64_2)
+			t.Errorf("[Hash128] key: '%s', seed: '%d': 0x%x-0x%x (want 0x%x-0x%x)", elem.s, elem.seed, v1, v2, elem.h64_1, elem.h64_2)
 		}
 	}
 }
@@ -92,7 +92,8 @@ func TestIncremental(t *testing.T) {
 	for _, elem := range data {
 		h32 := New32WithSeed(elem.seed)
 		h128 := New128WithSeed(elem.seed)
-		for i, j, k := 0, 0, len(elem.s); i < k; i = j {
+		var i, j int
+		for k := len(elem.s); i < k; i = j {
 			j = 2*i + 3
 			if j > k {
 				j = k
@@ -104,10 +105,10 @@ func TestIncremental(t *testing.T) {
 		}
 		println()
 		if v := h32.Sum32(); v != elem.h32 {
-			t.Errorf("'%s': 0x%x (want 0x%x)", elem.s, v, elem.h32)
+			t.Errorf("[Hash32] key: '%s', seed: '%d': 0x%x (want 0x%x)", elem.s, elem.seed, v, elem.h32)
 		}
 		if v1, v2 := h128.Sum128(); v1 != elem.h64_1 || v2 != elem.h64_2 {
-			t.Errorf("'%s': 0x%x-0x%x (want 0x%x-0x%x)", elem.s, v1, v2, elem.h64_1, elem.h64_2)
+			t.Errorf("[Hash128] key: '%s', seed: '%d': 0x%x-0x%x (want 0x%x-0x%x)", elem.s, elem.seed, v1, v2, elem.h64_1, elem.h64_2)
 		}
 	}
 }