diff --git a/graph/bolt/all_iterator.go b/graph/bolt/all_iterator.go
index 5d8bf89..4cd017e 100644
--- a/graph/bolt/all_iterator.go
+++ b/graph/bolt/all_iterator.go
@@ -182,7 +182,7 @@ func (it *AllIterator) Describe() graph.Description {
 	size, _ := it.Size()
 	return graph.Description{
 		UID:       it.UID(),
-		Type:      it.Type().String(),
+		Type:      it.Type(),
 		Tags:      it.tags.Tags(),
 		Size:      size,
 		Direction: it.dir,
diff --git a/graph/bolt/iterator.go b/graph/bolt/iterator.go
index 8709ebe..ec298de 100644
--- a/graph/bolt/iterator.go
+++ b/graph/bolt/iterator.go
@@ -294,7 +294,7 @@ func (it *Iterator) Describe() graph.Description {
 	return graph.Description{
 		UID:       it.UID(),
 		Name:      it.qs.NameOf(&Token{it.bucket, it.checkID}),
-		Type:      it.Type().String(),
+		Type:      it.Type(),
 		Tags:      it.tags.Tags(),
 		Size:      it.size,
 		Direction: it.dir,
diff --git a/graph/iterator.go b/graph/iterator.go
index 3a74dc6..4442ea5 100644
--- a/graph/iterator.go
+++ b/graph/iterator.go
@@ -17,11 +17,12 @@ package graph
 // Define the general iterator interface.
 
 import (
-	"github.com/google/cayley/quad"
+	"fmt"
 	"strings"
 	"sync"
 
 	"github.com/barakmich/glog"
+	"github.com/google/cayley/quad"
 )
 
 type Tagger struct {
@@ -144,7 +145,7 @@ type Iterator interface {
 type Description struct {
 	UID       uint64         `json:",omitempty"`
 	Name      string         `json:",omitempty"`
-	Type      string         `json:",omitempty"`
+	Type      Type           `json:",omitempty"`
 	Tags      []string       `json:",omitempty"`
 	Size      int64          `json:",omitempty"`
 	Direction quad.Direction `json:",omitempty"`
@@ -267,9 +268,27 @@ func (t Type) String() string {
 	return types[t]
 }
 
+func (t *Type) MarshalText() (text []byte, err error) {
+	if *t < 0 || int(*t) >= len(types) {
+		return nil, fmt.Errorf("graph: illegal iterator type: %d", *t)
+	}
+	return []byte(types[*t]), nil
+}
+
+func (t *Type) UnmarshalText(text []byte) error {
+	s := string(text)
+	for i, c := range types[1:] {
+		if c == s {
+			*t = Type(i + 1)
+			return nil
+		}
+	}
+	return fmt.Errorf("graph: unknown iterator label: %q", text)
+}
+
 type StatsContainer struct {
 	UID  uint64
-	Type string
+	Type Type
 	IteratorStats
 	SubIts []StatsContainer
 }
@@ -277,7 +296,7 @@ type StatsContainer struct {
 func DumpStats(it Iterator) StatsContainer {
 	var out StatsContainer
 	out.IteratorStats = it.Stats()
-	out.Type = it.Type().String()
+	out.Type = it.Type()
 	out.UID = it.UID()
 	for _, sub := range it.SubIterators() {
 		out.SubIts = append(out.SubIts, DumpStats(sub))
diff --git a/graph/iterator/all_iterator.go b/graph/iterator/all_iterator.go
index c89c44c..d937ce4 100644
--- a/graph/iterator/all_iterator.go
+++ b/graph/iterator/all_iterator.go
@@ -81,7 +81,7 @@ func (it *Int64) TagResults(dst map[string]graph.Value) {
 func (it *Int64) Describe() graph.Description {
 	return graph.Description{
 		UID:  it.UID(),
-		Type: it.Type().String(),
+		Type: it.Type(),
 		Tags: it.tags.Tags(),
 	}
 }
diff --git a/graph/iterator/and_iterator.go b/graph/iterator/and_iterator.go
index 64c68f0..3764600 100644
--- a/graph/iterator/and_iterator.go
+++ b/graph/iterator/and_iterator.go
@@ -116,7 +116,7 @@ func (it *And) Describe() graph.Description {
 	primary := it.primaryIt.Describe()
 	return graph.Description{
 		UID:       it.UID(),
-		Type:      it.Type().String(),
+		Type:      it.Type(),
 		Tags:      it.tags.Tags(),
 		Iterator:  &primary,
 		Iterators: subIts,
diff --git a/graph/iterator/fixed_iterator.go b/graph/iterator/fixed_iterator.go
index 93d31b4..4a8afb9 100644
--- a/graph/iterator/fixed_iterator.go
+++ b/graph/iterator/fixed_iterator.go
@@ -107,7 +107,7 @@ func (it *Fixed) Describe() graph.Description {
 	return graph.Description{
 		UID:  it.UID(),
 		Name: value,
-		Type: it.Type().String(),
+		Type: it.Type(),
 		Tags: fixed,
 		Size: int64(len(it.values)),
 	}
diff --git a/graph/iterator/hasa_iterator.go b/graph/iterator/hasa_iterator.go
index fed6469..3788b40 100644
--- a/graph/iterator/hasa_iterator.go
+++ b/graph/iterator/hasa_iterator.go
@@ -131,7 +131,7 @@ func (it *HasA) Describe() graph.Description {
 	primary := it.primaryIt.Describe()
 	return graph.Description{
 		UID:       it.UID(),
-		Type:      it.Type().String(),
+		Type:      it.Type(),
 		Tags:      it.tags.Tags(),
 		Direction: it.dir,
 		Iterator:  &primary,
diff --git a/graph/iterator/iterator.go b/graph/iterator/iterator.go
index e1c98c9..954ddba 100644
--- a/graph/iterator/iterator.go
+++ b/graph/iterator/iterator.go
@@ -80,7 +80,7 @@ func (it *Null) Optimize() (graph.Iterator, bool) { return it, false }
 func (it *Null) Describe() graph.Description {
 	return graph.Description{
 		UID:  it.UID(),
-		Type: it.Type().String(),
+		Type: it.Type(),
 	}
 }
 
diff --git a/graph/iterator/linksto_iterator.go b/graph/iterator/linksto_iterator.go
index 5952cd1..99a8df5 100644
--- a/graph/iterator/linksto_iterator.go
+++ b/graph/iterator/linksto_iterator.go
@@ -109,7 +109,7 @@ func (it *LinksTo) Describe() graph.Description {
 	primary := it.primaryIt.Describe()
 	return graph.Description{
 		UID:       it.UID(),
-		Type:      it.Type().String(),
+		Type:      it.Type(),
 		Direction: it.dir,
 		Iterator:  &primary,
 	}
diff --git a/graph/iterator/materialize_iterator.go b/graph/iterator/materialize_iterator.go
index 7adb515..00b2102 100644
--- a/graph/iterator/materialize_iterator.go
+++ b/graph/iterator/materialize_iterator.go
@@ -119,7 +119,7 @@ func (it *Materialize) Describe() graph.Description {
 	primary := it.subIt.Describe()
 	return graph.Description{
 		UID:      it.UID(),
-		Type:     it.Type().String(),
+		Type:     it.Type(),
 		Tags:     it.tags.Tags(),
 		Size:     int64(len(it.values)),
 		Iterator: &primary,
diff --git a/graph/iterator/optional_iterator.go b/graph/iterator/optional_iterator.go
index 5622f59..bc65acc 100644
--- a/graph/iterator/optional_iterator.go
+++ b/graph/iterator/optional_iterator.go
@@ -121,7 +121,7 @@ func (it *Optional) Describe() graph.Description {
 	primary := it.subIt.Describe()
 	return graph.Description{
 		UID:      it.UID(),
-		Type:     it.Type().String(),
+		Type:     it.Type(),
 		Tags:     it.tags.Tags(),
 		Iterator: &primary,
 	}
diff --git a/graph/iterator/or_iterator.go b/graph/iterator/or_iterator.go
index 805ede0..6c58238 100644
--- a/graph/iterator/or_iterator.go
+++ b/graph/iterator/or_iterator.go
@@ -117,7 +117,7 @@ func (it *Or) Describe() graph.Description {
 	}
 	return graph.Description{
 		UID:       it.UID(),
-		Type:      it.Type().String(),
+		Type:      it.Type(),
 		Tags:      it.tags.Tags(),
 		Iterators: subIts,
 	}
diff --git a/graph/iterator/value_comparison_iterator.go b/graph/iterator/value_comparison_iterator.go
index dae9956..627b853 100644
--- a/graph/iterator/value_comparison_iterator.go
+++ b/graph/iterator/value_comparison_iterator.go
@@ -192,7 +192,7 @@ func (it *Comparison) Describe() graph.Description {
 	primary := it.subIt.Describe()
 	return graph.Description{
 		UID:      it.UID(),
-		Type:     it.Type().String(),
+		Type:     it.Type(),
 		Iterator: &primary,
 	}
 }
diff --git a/graph/iterator_test.go b/graph/iterator_test.go
new file mode 100644
index 0000000..3d6f14e
--- /dev/null
+++ b/graph/iterator_test.go
@@ -0,0 +1,45 @@
+// Copyright 2014 The Cayley Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package graph
+
+import (
+	"testing"
+)
+
+func TestTypeEncodingRoundtrip(t *testing.T) {
+	for i := Invalid; i <= Materialize; i++ {
+		text, err := i.MarshalText()
+		if err != nil {
+			t.Errorf("Unexpected error when marshaling %s: %v", i, err)
+		}
+		if string(text) != i.String() {
+			t.Errorf("Unexpected MarshalText result, got:%q expect:%q", i, text)
+		}
+		var m Type
+		err = m.UnmarshalText(text)
+		if i == Invalid {
+			if err == nil || err.Error() != `graph: unknown iterator label: "invalid"` {
+				t.Errorf("Unexpected error when unmarshaling %q: %v", text, err)
+			}
+		} else {
+			if err != nil {
+				t.Errorf("Unexpected error when unmarshaling %q: %v", text, err)
+			}
+		}
+		if m != i {
+			t.Errorf("Unexpected UnmarshalText result, got:Type(%d) expect:Type(%d)", m, i)
+		}
+	}
+}
diff --git a/graph/leveldb/all_iterator.go b/graph/leveldb/all_iterator.go
index 346a973..515133f 100644
--- a/graph/leveldb/all_iterator.go
+++ b/graph/leveldb/all_iterator.go
@@ -161,7 +161,7 @@ func (it *AllIterator) Describe() graph.Description {
 	size, _ := it.Size()
 	return graph.Description{
 		UID:       it.UID(),
-		Type:      it.Type().String(),
+		Type:      it.Type(),
 		Tags:      it.tags.Tags(),
 		Size:      size,
 		Direction: it.dir,
diff --git a/graph/leveldb/iterator.go b/graph/leveldb/iterator.go
index 8bdd86d..6ccd3fe 100644
--- a/graph/leveldb/iterator.go
+++ b/graph/leveldb/iterator.go
@@ -253,7 +253,7 @@ func (it *Iterator) Describe() graph.Description {
 	return graph.Description{
 		UID:       it.UID(),
 		Name:      it.qs.NameOf(Token(it.checkID)),
-		Type:      it.Type().String(),
+		Type:      it.Type(),
 		Tags:      it.tags.Tags(),
 		Size:      size,
 		Direction: it.dir,
diff --git a/graph/memstore/iterator.go b/graph/memstore/iterator.go
index fb1047e..d79e6c8 100644
--- a/graph/memstore/iterator.go
+++ b/graph/memstore/iterator.go
@@ -162,7 +162,7 @@ func (it *Iterator) Describe() graph.Description {
 	return graph.Description{
 		UID:  it.UID(),
 		Name: it.data,
-		Type: it.Type().String(),
+		Type: it.Type(),
 		Tags: it.tags.Tags(),
 		Size: size,
 	}
diff --git a/graph/mongo/iterator.go b/graph/mongo/iterator.go
index 40694fb..32bc472 100644
--- a/graph/mongo/iterator.go
+++ b/graph/mongo/iterator.go
@@ -217,7 +217,7 @@ func (it *Iterator) Describe() graph.Description {
 	return graph.Description{
 		UID:  it.UID(),
 		Name: fmt.Sprintf("%s/%s", it.name, it.hash),
-		Type: it.Type().String(),
+		Type: it.Type(),
 		Size: size,
 	}
 }