diff --git a/ast/map.go b/ast/map.go
new file mode 100644
index 0000000000..66cf3a9b9b
--- /dev/null
+++ b/ast/map.go
@@ -0,0 +1,89 @@
+// Copyright 2016 The OPA Authors.  All rights reserved.
+// Use of this source code is governed by an Apache2
+// license that can be found in the LICENSE file.
+
+package ast
+
+import (
+	"github.com/open-policy-agent/opa/util"
+)
+
+// ValueMap represents a key/value map between AST term values. Any type of term
+// can be used as a key in the map.
+type ValueMap struct {
+	hashMap *util.HashMap
+}
+
+// NewValueMap returns a new ValueMap.
+func NewValueMap() *ValueMap {
+	vs := &ValueMap{
+		hashMap: util.NewHashMap(valueEq, valueHash),
+	}
+	return vs
+}
+
+// Copy returns a shallow copy of the ValueMap.
+func (vs *ValueMap) Copy() *ValueMap {
+	cpy := NewValueMap()
+	cpy.hashMap = vs.hashMap.Copy()
+	return cpy
+}
+
+// Equal returns true if this ValueMap equals the other.
+func (vs *ValueMap) Equal(other *ValueMap) bool {
+	return vs.hashMap.Equal(other.hashMap)
+}
+
+// Get returns the value in the map for k.
+func (vs *ValueMap) Get(k Value) Value {
+	if v, ok := vs.hashMap.Get(k); ok {
+		return v.(Value)
+	}
+	return nil
+}
+
+// Hash returns a hash code for this ValueMap.
+func (vs *ValueMap) Hash() int {
+	return vs.hashMap.Hash()
+}
+
+// Iter calls the iter function for each key/value pair in the map. If the iter
+// function returns true, iteration stops.
+func (vs *ValueMap) Iter(iter func(Value, Value) bool) bool {
+	return vs.hashMap.Iter(func(kt, vt util.T) bool {
+		k := kt.(Value)
+		v := vt.(Value)
+		return iter(k, v)
+	})
+}
+
+// Put inserts a key k into the map with value v.
+func (vs *ValueMap) Put(k, v Value) {
+	vs.hashMap.Put(k, v)
+}
+
+// Delete removes a key k from the map.
+func (vs *ValueMap) Delete(k Value) {
+	vs.hashMap.Delete(k)
+}
+
+// Update returns a new ValueMap that contains the union of this ValueMap and
+// the other. Overlapping keys are replaced with values from the other.
+func (vs *ValueMap) Update(other *ValueMap) *ValueMap {
+	new := vs.hashMap.Update(other.hashMap)
+	return &ValueMap{new}
+}
+
+func (vs *ValueMap) String() string {
+	return vs.hashMap.String()
+}
+
+func valueHash(v util.T) int {
+	return v.(Value).Hash()
+}
+
+func valueEq(a, b util.T) bool {
+	av := a.(Value)
+	bv := b.(Value)
+	return av.Equal(bv)
+}
diff --git a/ast/map_test.go b/ast/map_test.go
new file mode 100644
index 0000000000..97e4a30d03
--- /dev/null
+++ b/ast/map_test.go
@@ -0,0 +1,97 @@
+// Copyright 2016 The OPA Authors.  All rights reserved.
+// Use of this source code is governed by an Apache2
+// license that can be found in the LICENSE file.
+
+package ast
+
+import (
+	"reflect"
+	"sort"
+	"testing"
+)
+
+func TestValueMapOverwrite(t *testing.T) {
+
+	a := NewValueMap()
+	b := NewValueMap()
+	a.Put(String("x"), String("foo"))
+	a.Put(String("x"), String("bar"))
+	if a.Get(String("x")) != String("bar") {
+		t.Fatalf("Expected a['x'] = 'bar' but got: %v", a.Get(String("x")))
+	}
+
+	a.Put(String("z"), String("corge"))
+	b.Put(String("y"), String("baz"))
+	b.Put(String("x"), String("qux"))
+
+	c := a.Update(b)
+
+	if c.Get(String("x")) != String("qux") {
+		t.Fatalf("Expected c['x'] = 'qux' but got: %v", c.Get(String("x")))
+	}
+}
+
+func TestValueMapIter(t *testing.T) {
+	a := NewValueMap()
+	a.Put(String("x"), String("foo"))
+	a.Put(String("y"), String("bar"))
+	a.Put(String("z"), String("baz"))
+	values := []string{}
+	a.Iter(func(k, v Value) bool {
+		values = append(values, string(v.(String)))
+		return false
+	})
+	sort.Strings(values)
+	expected := []string{"bar", "baz", "foo"}
+	if !reflect.DeepEqual(values, expected) {
+		t.Fatalf("Unexpected value from iteration: %v", values)
+	}
+}
+
+func TestValueMapCopy(t *testing.T) {
+	a := NewValueMap()
+	a.Put(String("x"), String("foo"))
+	a.Put(String("y"), String("bar"))
+	b := a.Copy()
+	b.Delete(String("y"))
+	if a.Get(String("y")) != String("bar") {
+		t.Fatalf("Unexpected a['y'] value: %v", a.Get(String("y")))
+	}
+}
+
+func TestValueMapEqual(t *testing.T) {
+	a := NewValueMap()
+	a.Put(String("x"), String("foo"))
+	a.Put(String("y"), String("bar"))
+	b := a.Copy()
+	if !a.Equal(b) {
+		t.Fatalf("Expected a == b but not for: %v / %v", a, b)
+	}
+	if a.Hash() != b.Hash() {
+		t.Fatalf("Expected a.Hash() == b.Hash() but not for: %v / %v", a, b)
+	}
+	a.Delete(String("x"))
+	if a.Equal(b) {
+		t.Fatalf("Expected a != b but not for: %v / %v", a, b)
+	}
+}
+
+func TestValueMapGetMissing(t *testing.T) {
+	a := NewValueMap()
+	a.Put(String("x"), String("foo"))
+	a.Put(String("y"), String("bar"))
+	if a.Get(String("z")) != nil {
+		t.Fatalf("Expected a['z'] = nil but got: %v", a.Get(String("z")))
+	}
+}
+
+func TestValueMapString(t *testing.T) {
+	a := NewValueMap()
+	a.Put(MustParseRef("a.b.c[x]"), String("foo"))
+	a.Put(Var("x"), Number(1))
+	expected := `{a.b.c[x]: "foo", x: 1}`
+	result := a.String()
+	if expected != result {
+		t.Fatalf("Expected %v but got: %v", expected, result)
+	}
+}
diff --git a/server/server.go b/server/server.go
index 999231337e..15f66f59b8 100644
--- a/server/server.go
+++ b/server/server.go
@@ -722,8 +722,8 @@ func getPretty(p []string) bool {
 	return false
 }
 
-func parseGlobals(g []string) (*storage.Bindings, error) {
-	globals := storage.NewBindings()
+func parseGlobals(g []string) (*ast.ValueMap, error) {
+	globals := ast.NewValueMap()
 	for _, g := range g {
 		vs := strings.SplitN(g, ":", 2)
 		k, err := ast.ParseTerm(vs[0])
diff --git a/server/server_test.go b/server/server_test.go
index 162c5f3d33..8b7b8efe7e 100644
--- a/server/server_test.go
+++ b/server/server_test.go
@@ -525,7 +525,7 @@ func TestGlobalParsing(t *testing.T) {
 				t.Errorf("%v (#%d): Unexpected error: %v", tc.note, i+1, err)
 				continue
 			}
-			exp := storage.NewBindings()
+			exp := ast.NewValueMap()
 			for _, i := range ast.MustParseTerm(e).Value.(ast.Object) {
 				exp.Put(i[0].Value, i[1].Value)
 			}
diff --git a/storage/bindings.go b/storage/bindings.go
deleted file mode 100644
index 9e3eebb0db..0000000000
--- a/storage/bindings.go
+++ /dev/null
@@ -1,93 +0,0 @@
-// Copyright 2016 The OPA Authors.  All rights reserved.
-// Use of this source code is governed by an Apache2
-// license that can be found in the LICENSE file.
-
-package storage
-
-import (
-	"github.com/open-policy-agent/opa/ast"
-	"github.com/open-policy-agent/opa/util"
-)
-
-// Bindings represents a mapping between key/value pairs.
-// The key/value pairs are AST values contained in expressions.
-// Insertion of a key/value pair represents unification of the
-// two values.
-//
-// TODO(tsandall): rename to ValueMap and move into ast package.
-type Bindings struct {
-	hashMap *util.HashMap
-}
-
-// NewBindings returns a new empty set of bindings.
-func NewBindings() *Bindings {
-	b := &Bindings{
-		hashMap: util.NewHashMap(bindingsEq, bindingsHash),
-	}
-	return b
-}
-
-// Copy returns a shallow copy of these bindings.
-func (b *Bindings) Copy() *Bindings {
-	cpy := NewBindings()
-	cpy.hashMap = b.hashMap.Copy()
-	return cpy
-}
-
-// Equal returns true if these bindings equal the other bindings.
-// Two bindings are equal if they contain the same key/value pairs.
-func (b *Bindings) Equal(other *Bindings) bool {
-	return b.hashMap.Equal(other.hashMap)
-}
-
-// Get returns the binding for the given key.
-func (b *Bindings) Get(k ast.Value) ast.Value {
-	if v, ok := b.hashMap.Get(k); ok {
-		return v.(ast.Value)
-	}
-	return nil
-}
-
-// Hash returns the hash code for the bindings.
-func (b *Bindings) Hash() int {
-	return b.hashMap.Hash()
-}
-
-// Iter iterates the bindings and calls the "iter" function for each key/value pair.
-func (b *Bindings) Iter(iter func(ast.Value, ast.Value) bool) bool {
-	return b.hashMap.Iter(func(kt, vt util.T) bool {
-		k := kt.(ast.Value)
-		v := vt.(ast.Value)
-		return iter(k, v)
-	})
-}
-
-// Put inserts a key/value pair.
-func (b *Bindings) Put(k, v ast.Value) {
-	b.hashMap.Put(k, v)
-}
-
-// Delete removes a key/value pair.
-func (b *Bindings) Delete(k ast.Value) {
-	b.hashMap.Delete(k)
-}
-
-// Update returns new bindings that are the union of these bindings and the other bindings.
-func (b *Bindings) Update(other *Bindings) *Bindings {
-	new := b.hashMap.Update(other.hashMap)
-	return &Bindings{new}
-}
-
-func (b *Bindings) String() string {
-	return b.hashMap.String()
-}
-
-func bindingsHash(v util.T) int {
-	return v.(ast.Value).Hash()
-}
-
-func bindingsEq(a, b util.T) bool {
-	av := a.(ast.Value)
-	bv := b.(ast.Value)
-	return av.Equal(bv)
-}
diff --git a/storage/index.go b/storage/index.go
index 8ecb5f9438..6fe7e3e034 100644
--- a/storage/index.go
+++ b/storage/index.go
@@ -53,7 +53,7 @@ func newIndices() *indices {
 func (ind *indices) Build(store Store, txn Transaction, ref ast.Ref) error {
 	index := newBindingIndex()
 	ind.registerTriggers(store)
-	err := iterStorage(store, txn, ref, ast.EmptyRef(), NewBindings(), func(bindings *Bindings, val interface{}) {
+	err := iterStorage(store, txn, ref, ast.EmptyRef(), ast.NewValueMap(), func(bindings *ast.ValueMap, val interface{}) {
 		index.Add(val, bindings)
 	})
 	if err != nil {
@@ -163,7 +163,7 @@ func newBindingIndex() *bindingIndex {
 
 // Add updates the index to include new bindings for the value.
 // If the bindings already exist for the value, no change is made.
-func (ind *bindingIndex) Add(val interface{}, bindings *Bindings) {
+func (ind *bindingIndex) Add(val interface{}, bindings *ast.ValueMap) {
 
 	node := ind.getNode(val)
 	if node != nil {
@@ -185,7 +185,7 @@ func (ind *bindingIndex) Add(val interface{}, bindings *Bindings) {
 }
 
 // Iter calls the iter function for each set of bindings for the value.
-func (ind *bindingIndex) Iter(val interface{}, iter func(*Bindings) error) error {
+func (ind *bindingIndex) Iter(val interface{}, iter func(*ast.ValueMap) error) error {
 	node := ind.getNode(val)
 	if node == nil {
 		return nil
@@ -219,7 +219,7 @@ func (ind *bindingIndex) String() string {
 }
 
 type bindingSetNode struct {
-	val  *Bindings
+	val  *ast.ValueMap
 	next *bindingSetNode
 }
 
@@ -233,7 +233,7 @@ func newBindingSet() *bindingSet {
 	}
 }
 
-func (set *bindingSet) Add(val *Bindings) {
+func (set *bindingSet) Add(val *ast.ValueMap) {
 	node := set.getNode(val)
 	if node != nil {
 		return
@@ -243,7 +243,7 @@ func (set *bindingSet) Add(val *Bindings) {
 	set.table[hashCode] = &bindingSetNode{val, head}
 }
 
-func (set *bindingSet) Iter(iter func(*Bindings) error) error {
+func (set *bindingSet) Iter(iter func(*ast.ValueMap) error) error {
 	for _, head := range set.table {
 		for entry := head; entry != nil; entry = entry.next {
 			if err := iter(entry.val); err != nil {
@@ -256,14 +256,14 @@ func (set *bindingSet) Iter(iter func(*Bindings) error) error {
 
 func (set *bindingSet) String() string {
 	buf := []string{}
-	set.Iter(func(bindings *Bindings) error {
+	set.Iter(func(bindings *ast.ValueMap) error {
 		buf = append(buf, bindings.String())
 		return nil
 	})
 	return "{" + strings.Join(buf, ", ") + "}"
 }
 
-func (set *bindingSet) getNode(val *Bindings) *bindingSetNode {
+func (set *bindingSet) getNode(val *ast.ValueMap) *bindingSetNode {
 	hashCode := val.Hash()
 	for entry := set.table[hashCode]; entry != nil; entry = entry.next {
 		if entry.val.Equal(val) {
@@ -304,7 +304,7 @@ func hash(v interface{}) int {
 	panic(fmt.Sprintf("illegal argument: %v (%T)", v, v))
 }
 
-func iterStorage(store Store, txn Transaction, ref ast.Ref, path ast.Ref, bindings *Bindings, iter func(*Bindings, interface{})) error {
+func iterStorage(store Store, txn Transaction, ref ast.Ref, path ast.Ref, bindings *ast.ValueMap, iter func(*ast.ValueMap, interface{})) error {
 
 	if len(ref) == 0 {
 		node, err := store.Read(txn, path)
diff --git a/storage/index_test.go b/storage/index_test.go
index 65353bb79f..94942850a1 100644
--- a/storage/index_test.go
+++ b/storage/index_test.go
@@ -105,7 +105,7 @@ func assertBindingsEqual(t *testing.T, note string, index *bindingIndex, value i
 
 	expected := loadExpectedBindings(expectedStr)
 
-	err := index.Iter(value, func(bindings *Bindings) error {
+	err := index.Iter(value, func(bindings *ast.ValueMap) error {
 		for j := range expected {
 			if expected[j].Equal(bindings) {
 				tmp := expected[:j]
@@ -127,14 +127,14 @@ func assertBindingsEqual(t *testing.T, note string, index *bindingIndex, value i
 	}
 }
 
-func loadExpectedBindings(input string) []*Bindings {
+func loadExpectedBindings(input string) []*ast.ValueMap {
 	var data []map[string]interface{}
 	if err := json.Unmarshal([]byte(input), &data); err != nil {
 		panic(err)
 	}
-	var expected []*Bindings
+	var expected []*ast.ValueMap
 	for _, bindings := range data {
-		buf := NewBindings()
+		buf := ast.NewValueMap()
 		for k, v := range bindings {
 			switch v := v.(type) {
 			case string:
diff --git a/storage/storage.go b/storage/storage.go
index 607b77b077..6124f2b687 100644
--- a/storage/storage.go
+++ b/storage/storage.go
@@ -303,7 +303,7 @@ func (s *Storage) IndexExists(ref ast.Ref) bool {
 // Index invokes the iterator with bindings for each variable in the reference
 // that if plugged into the reference, would locate a document with a matching
 // value.
-func (s *Storage) Index(txn Transaction, ref ast.Ref, value interface{}, iter func(*Bindings) error) error {
+func (s *Storage) Index(txn Transaction, ref ast.Ref, value interface{}, iter func(*ast.ValueMap) error) error {
 
 	idx := s.indices.Get(ref)
 	if idx == nil {
diff --git a/test/scheduler/scheduler_bench_test.go b/test/scheduler/scheduler_bench_test.go
index c086e964c1..acce939a99 100644
--- a/test/scheduler/scheduler_bench_test.go
+++ b/test/scheduler/scheduler_bench_test.go
@@ -65,7 +65,7 @@ func setupBenchmark(nodes int, pods int) *topdown.QueryParams {
 	store := storage.New(storage.InMemoryConfig())
 
 	// parameter setup
-	globals := storage.NewBindings()
+	globals := ast.NewValueMap()
 	req := ast.MustParseTerm(requestedPod).Value
 	globals.Put(ast.Var("requested_pod"), req)
 	path := []interface{}{"opa", "test", "scheduler", "fit"}
diff --git a/test/scheduler/scheduler_test.go b/test/scheduler/scheduler_test.go
index 5a25fb2c2b..236c8a1143 100644
--- a/test/scheduler/scheduler_test.go
+++ b/test/scheduler/scheduler_test.go
@@ -54,7 +54,7 @@ func setup(t *testing.T, filename string) *topdown.QueryParams {
 	})
 
 	// parameter setup
-	globals := storage.NewBindings()
+	globals := ast.NewValueMap()
 	req := ast.MustParseTerm(requestedPod).Value
 	globals.Put(ast.Var("requested_pod"), req)
 	path := []interface{}{"opa", "test", "scheduler", "fit"}
diff --git a/topdown/example_test.go b/topdown/example_test.go
index 2355a133f2..691b02b3b9 100644
--- a/topdown/example_test.go
+++ b/topdown/example_test.go
@@ -104,7 +104,7 @@ func ExampleQuery() {
 	// Prepare the query parameters. Queries execute against the policy engine's storage and can
 	// accept additional documents (which are referred to as "globals"). In this case we have no
 	// additional documents.
-	globals := storage.NewBindings()
+	globals := ast.NewValueMap()
 	params := topdown.NewQueryParams(compiler, store, txn, globals, []interface{}{"opa", "example", "p"})
 
 	// Execute the query against "p".
diff --git a/topdown/topdown.go b/topdown/topdown.go
index a90614414a..c070ed346c 100644
--- a/topdown/topdown.go
+++ b/topdown/topdown.go
@@ -17,8 +17,8 @@ import (
 type Context struct {
 	Query    ast.Body
 	Compiler *ast.Compiler
-	Globals  *storage.Bindings
-	Locals   *storage.Bindings
+	Globals  *ast.ValueMap
+	Locals   *ast.ValueMap
 	Index    int
 	Previous *Context
 	Store    *storage.Storage
@@ -37,8 +37,8 @@ func NewContext(query ast.Body, compiler *ast.Compiler, store *storage.Storage,
 	return &Context{
 		Query:    query,
 		Compiler: compiler,
-		Globals:  storage.NewBindings(),
-		Locals:   storage.NewBindings(),
+		Globals:  ast.NewValueMap(),
+		Locals:   ast.NewValueMap(),
 		Store:    store,
 		txn:      txn,
 		cache:    newContextCache(),
@@ -85,7 +85,7 @@ func (ctx *Context) Unbind(undo *Undo) {
 }
 
 // Child returns a new context to evaluate a query that was referenced by this context.
-func (ctx *Context) Child(query ast.Body, locals *storage.Bindings) *Context {
+func (ctx *Context) Child(query ast.Body, locals *ast.ValueMap) *Context {
 	cpy := *ctx
 	cpy.Query = query
 	cpy.Locals = locals
@@ -352,13 +352,13 @@ type QueryParams struct {
 	Compiler    *ast.Compiler
 	Store       *storage.Storage
 	Transaction storage.Transaction
-	Globals     *storage.Bindings
+	Globals     *ast.ValueMap
 	Tracer      Tracer
 	Path        []interface{}
 }
 
 // NewQueryParams returns a new QueryParams.
-func NewQueryParams(compiler *ast.Compiler, store *storage.Storage, txn storage.Transaction, globals *storage.Bindings, path []interface{}) *QueryParams {
+func NewQueryParams(compiler *ast.Compiler, store *storage.Storage, txn storage.Transaction, globals *ast.ValueMap, path []interface{}) *QueryParams {
 	return &QueryParams{
 		Compiler:    compiler,
 		Store:       store,
@@ -374,7 +374,7 @@ func (q *QueryParams) NewContext(body ast.Body) *Context {
 		Query:    body,
 		Compiler: q.Compiler,
 		Globals:  q.Globals,
-		Locals:   storage.NewBindings(),
+		Locals:   ast.NewValueMap(),
 		Store:    q.Store,
 		Tracer:   q.Tracer,
 		txn:      q.Transaction,
@@ -991,7 +991,7 @@ func evalRefRuleCompleteDoc(ctx *Context, ref ast.Ref, suffix ast.Ref, rules []*
 
 	for _, rule := range rules {
 
-		bindings := storage.NewBindings()
+		bindings := ast.NewValueMap()
 		child := ctx.Child(rule.Body, bindings)
 
 		err := Eval(child, func(child *Context) error {
@@ -1039,7 +1039,7 @@ func evalRefRulePartialObjectDoc(ctx *Context, ref ast.Ref, path ast.Ref, rule *
 	// a recursive binding if we unified "key" with "rule.Key.Value". If unification
 	// is improved to handle namespacing, this can be revisited.
 	if !key.IsGround() {
-		child := ctx.Child(rule.Body, storage.NewBindings())
+		child := ctx.Child(rule.Body, ast.NewValueMap())
 		return Eval(child, func(child *Context) error {
 
 			key := PlugValue(rule.Key.Value, child)
@@ -1093,7 +1093,7 @@ func evalRefRulePartialObjectDoc(ctx *Context, ref ast.Ref, path ast.Ref, rule *
 		}
 	}
 
-	child := ctx.Child(rule.Body, storage.NewBindings())
+	child := ctx.Child(rule.Body, ast.NewValueMap())
 	_, err := evalEqUnify(child, key, rule.Key.Value, nil, func(child *Context) error {
 		return Eval(child, func(child *Context) error {
 			value := PlugValue(rule.Value.Value, child)
@@ -1143,7 +1143,7 @@ func evalRefRulePartialObjectDocFull(ctx *Context, ref ast.Ref, rules []*ast.Rul
 
 	for _, rule := range rules {
 
-		bindings := storage.NewBindings()
+		bindings := ast.NewValueMap()
 		child := ctx.Child(rule.Body, bindings)
 
 		err := Eval(child, func(child *Context) error {
@@ -1188,7 +1188,7 @@ func evalRefRulePartialSetDoc(ctx *Context, ref ast.Ref, path ast.Ref, rule *ast
 
 	// See comment in evalRefRulePartialObjectDoc about the two branches below.
 	if !key.IsGround() {
-		child := ctx.Child(rule.Body, storage.NewBindings())
+		child := ctx.Child(rule.Body, ast.NewValueMap())
 
 		// TODO(tsandall): Currently this evaluates the child query without any
 		// bindings from the current context. In cases where the key is partially
@@ -1214,7 +1214,7 @@ func evalRefRulePartialSetDoc(ctx *Context, ref ast.Ref, path ast.Ref, rule *ast
 		})
 	}
 
-	child := ctx.Child(rule.Body, storage.NewBindings())
+	child := ctx.Child(rule.Body, ast.NewValueMap())
 
 	_, err := evalEqUnify(child, key, rule.Key.Value, nil, func(child *Context) error {
 		return Eval(child, func(child *Context) error {
@@ -1412,7 +1412,7 @@ func evalTermsIndexed(ctx *Context, iter Iterator, indexed ast.Ref, nonIndexed *
 
 		// Iterate the bindings for the indexed term that when applied to the reference
 		// would locate the non-indexed value obtained above.
-		return ctx.Store.Index(ctx.txn, indexed, nonIndexedValue, func(bindings *storage.Bindings) error {
+		return ctx.Store.Index(ctx.txn, indexed, nonIndexedValue, func(bindings *ast.ValueMap) error {
 			var prev *Undo
 			bindings.Iter(func(k, v ast.Value) bool {
 				prev = ctx.Bind(k, v, prev)
diff --git a/topdown/topdown_test.go b/topdown/topdown_test.go
index 3798a1a78c..0837786dc4 100644
--- a/topdown/topdown_test.go
+++ b/topdown/topdown_test.go
@@ -1251,14 +1251,14 @@ func compileRules(imports []string, input []string) *ast.Compiler {
 	return c
 }
 
-func loadExpectedBindings(input string) []*storage.Bindings {
+func loadExpectedBindings(input string) []*ast.ValueMap {
 	var data []map[string]interface{}
 	if err := json.Unmarshal([]byte(input), &data); err != nil {
 		panic(err)
 	}
-	var expected []*storage.Bindings
+	var expected []*ast.ValueMap
 	for _, bindings := range data {
-		buf := storage.NewBindings()
+		buf := ast.NewValueMap()
 		for k, v := range bindings {
 			switch v := v.(type) {
 			case string:
@@ -1380,7 +1380,7 @@ func runTopDownTestCase(t *testing.T, data map[string]interface{}, note string,
 
 func assertTopDown(t *testing.T, compiler *ast.Compiler, store *storage.Storage, note string, path []string, globals string, expected interface{}) {
 
-	g := storage.NewBindings()
+	g := ast.NewValueMap()
 	for _, i := range ast.MustParseTerm(globals).Value.(ast.Object) {
 		g.Put(i[0].Value, i[1].Value)
 	}
diff --git a/topdown/tracer_test.go b/topdown/tracer_test.go
index 6c18f7b2ad..2fa4ec4309 100644
--- a/topdown/tracer_test.go
+++ b/topdown/tracer_test.go
@@ -8,6 +8,7 @@ import (
 	"fmt"
 	"testing"
 
+	"github.com/open-policy-agent/opa/ast"
 	"github.com/open-policy-agent/opa/storage"
 	"github.com/open-policy-agent/opa/util"
 )
@@ -35,7 +36,7 @@ func TestTracer(t *testing.T) {
 
 	tracer := &mockTracer{[]string{}}
 
-	params := NewQueryParams(compiler, store, txn, storage.NewBindings(), []interface{}{"p"})
+	params := NewQueryParams(compiler, store, txn, ast.NewValueMap(), []interface{}{"p"})
 	params.Tracer = tracer
 
 	result, err := Query(params)