diff --git a/helper/schema/field_reader_config_test.go b/helper/schema/field_reader_config_test.go
index 01cc1d703..8ca0a2fbe 100644
--- a/helper/schema/field_reader_config_test.go
+++ b/helper/schema/field_reader_config_test.go
@@ -1,11 +1,14 @@
 package schema
 
 import (
+	"bytes"
+	"fmt"
 	"reflect"
 	"testing"
 
 	"github.com/hashicorp/hil/ast"
 	"github.com/hashicorp/terraform/config"
+	"github.com/hashicorp/terraform/helper/hashcode"
 	"github.com/hashicorp/terraform/terraform"
 )
 
@@ -391,6 +394,138 @@ func TestConfigFieldReader_ComputedSet(t *testing.T) {
 	}
 }
 
+func TestConfigFieldReader_computedComplexSet(t *testing.T) {
+	hashfunc := func(v interface{}) int {
+		var buf bytes.Buffer
+		m := v.(map[string]interface{})
+		buf.WriteString(fmt.Sprintf("%s-", m["name"].(string)))
+		buf.WriteString(fmt.Sprintf("%s-", m["vhd_uri"].(string)))
+		return hashcode.String(buf.String())
+	}
+
+	schema := map[string]*Schema{
+		"set": &Schema{
+			Type: TypeSet,
+			Elem: &Resource{
+				Schema: map[string]*Schema{
+					"name": {
+						Type:     TypeString,
+						Required: true,
+					},
+
+					"vhd_uri": {
+						Type:     TypeString,
+						Required: true,
+					},
+				},
+			},
+			Set: hashfunc,
+		},
+	}
+
+	cases := map[string]struct {
+		Addr   []string
+		Result FieldReadResult
+		Config *terraform.ResourceConfig
+		Err    bool
+	}{
+		"set, normal": {
+			[]string{"set"},
+			FieldReadResult{
+				Value: map[string]interface{}{
+					"532860136": map[string]interface{}{
+						"name":    "myosdisk1",
+						"vhd_uri": "bar",
+					},
+				},
+				Exists:   true,
+				Computed: false,
+			},
+			testConfig(t, map[string]interface{}{
+				"set": []interface{}{
+					map[string]interface{}{
+						"name":    "myosdisk1",
+						"vhd_uri": "bar",
+					},
+				},
+			}),
+			false,
+		},
+
+		"set, computed element": {
+			[]string{"set"},
+			FieldReadResult{
+				Value: map[string]interface{}{
+					"~3596295623": map[string]interface{}{
+						"name":    "myosdisk1",
+						"vhd_uri": "${var.foo}/bar",
+					},
+				},
+				Exists:   true,
+				Computed: false,
+			},
+			testConfigInterpolate(t, map[string]interface{}{
+				"set": []interface{}{
+					map[string]interface{}{
+						"name":    "myosdisk1",
+						"vhd_uri": "${var.foo}/bar",
+					},
+				},
+			}, map[string]ast.Variable{
+				"var.foo": ast.Variable{
+					Value: config.UnknownVariableValue,
+					Type:  ast.TypeUnknown,
+				},
+			}),
+			false,
+		},
+
+		"set, computed element single": {
+			[]string{"set", "~3596295623", "vhd_uri"},
+			FieldReadResult{
+				Value:    "${var.foo}/bar",
+				Exists:   true,
+				Computed: true,
+			},
+			testConfigInterpolate(t, map[string]interface{}{
+				"set": []interface{}{
+					map[string]interface{}{
+						"name":    "myosdisk1",
+						"vhd_uri": "${var.foo}/bar",
+					},
+				},
+			}, map[string]ast.Variable{
+				"var.foo": ast.Variable{
+					Value: config.UnknownVariableValue,
+					Type:  ast.TypeUnknown,
+				},
+			}),
+			false,
+		},
+	}
+
+	for name, tc := range cases {
+		r := &ConfigFieldReader{
+			Schema: schema,
+			Config: tc.Config,
+		}
+		out, err := r.ReadField(tc.Addr)
+		if err != nil != tc.Err {
+			t.Fatalf("%s: err: %s", name, err)
+		}
+		if s, ok := out.Value.(*Set); ok {
+			// If it is a set, convert to the raw map
+			out.Value = s.m
+			if len(s.m) == 0 {
+				out.Value = nil
+			}
+		}
+		if !reflect.DeepEqual(tc.Result, out) {
+			t.Fatalf("%s: bad: %#v", name, out)
+		}
+	}
+}
+
 func testConfig(
 	t *testing.T, raw map[string]interface{}) *terraform.ResourceConfig {
 	return testConfigInterpolate(t, raw, nil)
diff --git a/terraform/interpolate.go b/terraform/interpolate.go
index 2bc74994f..3fb0b66a7 100644
--- a/terraform/interpolate.go
+++ b/terraform/interpolate.go
@@ -404,7 +404,8 @@ func (i *Interpolater) computeResourceVariable(
 	}
 
 	if attr, ok := r.Primary.Attributes[v.Field]; ok {
-		return &ast.Variable{Type: ast.TypeString, Value: attr}, nil
+		v, err := hil.InterfaceToVariable(attr)
+		return &v, err
 	}
 
 	// computed list or map attribute
diff --git a/terraform/interpolate_test.go b/terraform/interpolate_test.go
index 9b0925908..4eaf882bc 100644
--- a/terraform/interpolate_test.go
+++ b/terraform/interpolate_test.go
@@ -569,6 +569,44 @@ func TestInterpolator_resourceMultiAttributesComputed(t *testing.T) {
 	})
 }
 
+func TestInterpolator_resourceAttributeComputed(t *testing.T) {
+	lock := new(sync.RWMutex)
+	// The state would never be written with an UnknownVariableValue in it, but
+	// it can/does exist that way in memory during the plan phase.
+	state := &State{
+		Modules: []*ModuleState{
+			&ModuleState{
+				Path: rootModulePath,
+				Resources: map[string]*ResourceState{
+					"aws_route53_zone.yada": &ResourceState{
+						Type: "aws_route53_zone",
+						Primary: &InstanceState{
+							ID: "z-abc123",
+							Attributes: map[string]string{
+								"id": config.UnknownVariableValue,
+							},
+						},
+					},
+				},
+			},
+		},
+	}
+	i := &Interpolater{
+		Module:    testModule(t, "interpolate-multi-vars"),
+		StateLock: lock,
+		State:     state,
+	}
+
+	scope := &InterpolationScope{
+		Path: rootModulePath,
+	}
+
+	testInterpolate(t, i, scope, "aws_route53_zone.yada.id", ast.Variable{
+		Value: config.UnknownVariableValue,
+		Type:  ast.TypeUnknown,
+	})
+}
+
 func TestInterpolater_selfVarWithoutResource(t *testing.T) {
 	i := &Interpolater{}
 
diff --git a/vendor/github.com/hashicorp/hil/convert.go b/vendor/github.com/hashicorp/hil/convert.go
index 983b66baf..f2024d01c 100644
--- a/vendor/github.com/hashicorp/hil/convert.go
+++ b/vendor/github.com/hashicorp/hil/convert.go
@@ -55,7 +55,7 @@ func InterfaceToVariable(input interface{}) (ast.Variable, error) {
 	if err := hilMapstructureWeakDecode(input, &stringVal); err == nil {
 		// Special case the unknown value to turn into "unknown"
 		if stringVal == UnknownValue {
-			return ast.Variable{Type: ast.TypeUnknown}, nil
+			return ast.Variable{Value: UnknownValue, Type: ast.TypeUnknown}, nil
 		}
 
 		// Otherwise return the string value
diff --git a/vendor/vendor.json b/vendor/vendor.json
index 3d4d0f28a..3758fa418 100644
--- a/vendor/vendor.json
+++ b/vendor/vendor.json
@@ -1412,10 +1412,10 @@
 			"revisionTime": "2016-11-09T22:51:35Z"
 		},
 		{
-			"checksumSHA1": "mZhRldYjh9MAXzdi3zihMX0A/JU=",
+			"checksumSHA1": "PjLBj8sicHOz2ZzuaMTPZ09OuFs=",
 			"path": "github.com/hashicorp/hil",
-			"revision": "ce4ab742a9dd2bb6e55050337333b2c56666e5a0",
-			"revisionTime": "2016-10-27T15:25:34Z"
+			"revision": "a69e0a85dd050184c00f6080fce138f2dadb1a4c",
+			"revisionTime": "2016-11-11T01:09:07Z"
 		},
 		{
 			"checksumSHA1": "FFroNUb6Nn6xUQJMsVDTb4Cqzo4=",
@@ -1880,7 +1880,6 @@
 		},
 		{
 			"checksumSHA1": "DVXnx4zyb0wkeIdIRjwjvR7Dslo=",
-			"origin": "github.com/hashicorp/terraform/vendor/github.com/mitchellh/go-ps",
 			"path": "github.com/mitchellh/go-ps",
 			"revision": "e2d21980687ce16e58469d98dcee92d27fbbd7fb",
 			"revisionTime": "2016-08-22T16:54:47Z"