diff --git a/command/apply_test.go b/command/apply_test.go
index c27d184d8..4d86449ea 100644
--- a/command/apply_test.go
+++ b/command/apply_test.go
@@ -15,6 +15,7 @@ import (
 	"time"
 
 	"github.com/google/go-cmp/cmp"
+	"github.com/google/go-cmp/cmp/cmpopts"
 	"github.com/mitchellh/cli"
 	"github.com/zclconf/go-cty/cty"
 
@@ -1389,7 +1390,7 @@ func TestApply_backup(t *testing.T) {
 
 	actual := backupState.RootModule().Resources["test_instance.foo"]
 	expected := originalState.RootModule().Resources["test_instance.foo"]
-	if !cmp.Equal(actual, expected) {
+	if !cmp.Equal(actual, expected, cmpopts.EquateEmpty()) {
 		t.Fatalf(
 			"wrong aws_instance.foo state\n%s",
 			cmp.Diff(expected, actual, cmp.Transformer("bytesAsString", func(b []byte) string {
diff --git a/command/command_test.go b/command/command_test.go
index 8753028bc..d701c9a3b 100644
--- a/command/command_test.go
+++ b/command/command_test.go
@@ -7,8 +7,6 @@ import (
 	"encoding/json"
 	"flag"
 	"fmt"
-	"github.com/hashicorp/terraform/internal/initwd"
-	"github.com/hashicorp/terraform/registry"
 	"io"
 	"io/ioutil"
 	"log"
@@ -21,6 +19,9 @@ import (
 	"syscall"
 	"testing"
 
+	"github.com/hashicorp/terraform/internal/initwd"
+	"github.com/hashicorp/terraform/registry"
+
 	"github.com/hashicorp/terraform/addrs"
 	"github.com/hashicorp/terraform/configs"
 	"github.com/hashicorp/terraform/configs/configload"
@@ -266,7 +267,10 @@ func testState() *states.State {
 				Type: "test",
 			}.Absolute(addrs.RootModuleInstance),
 		)
-	})
+		// DeepCopy is used here to ensure our synthetic state matches exactly
+		// with a state that will have been copied during the command
+		// operation, and all fields have been copied correctly.
+	}).DeepCopy()
 }
 
 // writeStateForTesting is a helper that writes the given naked state to the
diff --git a/command/refresh_test.go b/command/refresh_test.go
index 603781466..5781c82d1 100644
--- a/command/refresh_test.go
+++ b/command/refresh_test.go
@@ -12,6 +12,8 @@ import (
 	"testing"
 
 	"github.com/davecgh/go-spew/spew"
+	"github.com/google/go-cmp/cmp"
+	"github.com/google/go-cmp/cmp/cmpopts"
 	"github.com/mitchellh/cli"
 	"github.com/zclconf/go-cty/cty"
 
@@ -557,8 +559,8 @@ func TestRefresh_backup(t *testing.T) {
 	}
 
 	newState := testStateRead(t, statePath)
-	if !reflect.DeepEqual(newState, state) {
-		t.Fatalf("bad: %#v", newState)
+	if !cmp.Equal(newState, state, cmpopts.EquateEmpty()) {
+		t.Fatalf("got:\n%s\nexpected:\n%s\n", newState, state)
 	}
 
 	newState = testStateRead(t, outPath)
diff --git a/states/state_deepcopy.go b/states/state_deepcopy.go
index ea717d00e..8664f3bea 100644
--- a/states/state_deepcopy.go
+++ b/states/state_deepcopy.go
@@ -147,7 +147,7 @@ func (obj *ResourceInstanceObjectSrc) DeepCopy() *ResourceInstanceObjectSrc {
 
 	var private []byte
 	if obj.Private != nil {
-		private := make([]byte, len(obj.Private))
+		private = make([]byte, len(obj.Private))
 		copy(private, obj.Private)
 	}
 
@@ -181,14 +181,17 @@ func (obj *ResourceInstanceObject) DeepCopy() *ResourceInstanceObject {
 
 	var private []byte
 	if obj.Private != nil {
-		private := make([]byte, len(obj.Private))
+		private = make([]byte, len(obj.Private))
 		copy(private, obj.Private)
 	}
 
-	// Some addrs.Referencable implementations are technically mutable, but
+	// Some addrs.Referenceable implementations are technically mutable, but
 	// we treat them as immutable by convention and so we don't deep-copy here.
-	dependencies := make([]addrs.Referenceable, len(obj.Dependencies))
-	copy(dependencies, obj.Dependencies)
+	var dependencies []addrs.Referenceable
+	if obj.Dependencies != nil {
+		dependencies = make([]addrs.Referenceable, len(obj.Dependencies))
+		copy(dependencies, obj.Dependencies)
+	}
 
 	return &ResourceInstanceObject{
 		Value:        obj.Value,
diff --git a/states/state_test.go b/states/state_test.go
index 8f941d179..618cfaafb 100644
--- a/states/state_test.go
+++ b/states/state_test.go
@@ -115,3 +115,62 @@ func TestState(t *testing.T) {
 		t.Error(problem)
 	}
 }
+
+func TestStateDeepCopy(t *testing.T) {
+	state := NewState()
+
+	rootModule := state.RootModule()
+	if rootModule == nil {
+		t.Errorf("root module is nil; want valid object")
+	}
+
+	rootModule.SetLocalValue("foo", cty.StringVal("foo value"))
+	rootModule.SetOutputValue("bar", cty.StringVal("bar value"), false)
+	rootModule.SetOutputValue("secret", cty.StringVal("secret value"), true)
+	rootModule.SetResourceInstanceCurrent(
+		addrs.Resource{
+			Mode: addrs.ManagedResourceMode,
+			Type: "test_thing",
+			Name: "baz",
+		}.Instance(addrs.IntKey(0)),
+		&ResourceInstanceObjectSrc{
+			Status:        ObjectReady,
+			SchemaVersion: 1,
+			AttrsJSON:     []byte(`{"woozles":"confuzles"}`),
+			Private:       []byte("private data"),
+			Dependencies:  []addrs.Referenceable{},
+		},
+		addrs.ProviderConfig{
+			Type: "test",
+		}.Absolute(addrs.RootModuleInstance),
+	)
+	rootModule.SetResourceInstanceCurrent(
+		addrs.Resource{
+			Mode: addrs.ManagedResourceMode,
+			Type: "test_thing",
+			Name: "bar",
+		}.Instance(addrs.IntKey(0)),
+		&ResourceInstanceObjectSrc{
+			Status:        ObjectReady,
+			SchemaVersion: 1,
+			AttrsJSON:     []byte(`{"woozles":"confuzles"}`),
+			Private:       []byte("private data"),
+			Dependencies: []addrs.Referenceable{addrs.Resource{
+				Mode: addrs.ManagedResourceMode,
+				Type: "test_thing",
+				Name: "baz",
+			}},
+		},
+		addrs.ProviderConfig{
+			Type: "test",
+		}.Absolute(addrs.RootModuleInstance),
+	)
+
+	childModule := state.EnsureModule(addrs.RootModuleInstance.Child("child", addrs.NoKey))
+	childModule.SetOutputValue("pizza", cty.StringVal("hawaiian"), false)
+
+	stateCopy := state.DeepCopy()
+	if !state.Equal(stateCopy) {
+		t.Fatalf("\nexpected:\n%q\ngot:\n%q\n", state, stateCopy)
+	}
+}