diff --git a/internal/configs/configschema/decoder_spec.go b/internal/configs/configschema/decoder_spec.go
index 333274503..19bea4917 100644
--- a/internal/configs/configschema/decoder_spec.go
+++ b/internal/configs/configschema/decoder_spec.go
@@ -211,9 +211,15 @@ func (a *Attribute) decoderSpec(name string) hcldec.Spec {
 // belong to their own cty.Object definitions. It is used in other functions
 // which themselves handle that recursion.
 func listOptionalAttrsFromObject(o *Object) []string {
-	var ret []string
+	ret := make([]string, 0)
+
+	// This is unlikely to happen outside of tests.
+	if o == nil {
+		return ret
+	}
+
 	for name, attr := range o.Attributes {
-		if attr.Optional == true {
+		if attr.Optional || attr.Computed {
 			ret = append(ret, name)
 		}
 	}
diff --git a/internal/configs/configschema/decoder_spec_test.go b/internal/configs/configschema/decoder_spec_test.go
index a6571eaa6..12fdee761 100644
--- a/internal/configs/configschema/decoder_spec_test.go
+++ b/internal/configs/configschema/decoder_spec_test.go
@@ -1,10 +1,12 @@
 package configschema
 
 import (
+	"sort"
 	"testing"
 
 	"github.com/apparentlymart/go-dump/dump"
 	"github.com/davecgh/go-spew/spew"
+	"github.com/google/go-cmp/cmp"
 
 	"github.com/hashicorp/hcl/v2"
 	"github.com/hashicorp/hcl/v2/hcldec"
@@ -885,3 +887,43 @@ func TestAttributeDecoderSpec_panic(t *testing.T) {
 	attrS.decoderSpec("attr")
 	t.Errorf("expected panic")
 }
+
+func TestListOptionalAttrsFromObject(t *testing.T) {
+	tests := []struct {
+		input *Object
+		want  []string
+	}{
+		{
+			nil,
+			[]string{},
+		},
+		{
+			&Object{},
+			[]string{},
+		},
+		{
+			&Object{
+				Nesting: NestingSingle,
+				Attributes: map[string]*Attribute{
+					"optional":          {Type: cty.String, Optional: true},
+					"required":          {Type: cty.Number, Required: true},
+					"computed":          {Type: cty.List(cty.Bool), Computed: true},
+					"optional_computed": {Type: cty.Map(cty.Bool), Optional: true, Computed: true},
+				},
+			},
+			[]string{"optional", "computed", "optional_computed"},
+		},
+	}
+
+	for _, test := range tests {
+		got := listOptionalAttrsFromObject(test.input)
+
+		// order is irrelevant
+		sort.Strings(got)
+		sort.Strings(test.want)
+
+		if diff := cmp.Diff(got, test.want); diff != "" {
+			t.Fatalf("wrong result: %s\n", diff)
+		}
+	}
+}
diff --git a/internal/configs/configschema/implied_type.go b/internal/configs/configschema/implied_type.go
index 4d4a042c3..58b995110 100644
--- a/internal/configs/configschema/implied_type.go
+++ b/internal/configs/configschema/implied_type.go
@@ -79,7 +79,7 @@ func (o *Object) ImpliedType() cty.Type {
 	case NestingSet:
 		return cty.Set(ret)
 	default: // Should never happen
-		panic("invalid Nesting")
+		return cty.EmptyObject
 	}
 }
 
diff --git a/internal/configs/configschema/implied_type_test.go b/internal/configs/configschema/implied_type_test.go
index 7cd0f7309..d36239615 100644
--- a/internal/configs/configschema/implied_type_test.go
+++ b/internal/configs/configschema/implied_type_test.go
@@ -37,6 +37,7 @@ func TestBlockImpliedType(t *testing.T) {
 					"optional_computed": {
 						Type:     cty.Map(cty.Bool),
 						Optional: true,
+						Computed: true,
 					},
 				},
 			},
@@ -132,26 +133,18 @@ func TestObjectImpliedType(t *testing.T) {
 			nil,
 			cty.EmptyObject,
 		},
+		"empty": {
+			&Object{},
+			cty.EmptyObject,
+		},
 		"attributes": {
 			&Object{
 				Nesting: NestingSingle,
 				Attributes: map[string]*Attribute{
-					"optional": {
-						Type:     cty.String,
-						Optional: true,
-					},
-					"required": {
-						Type:     cty.Number,
-						Required: true,
-					},
-					"computed": {
-						Type:     cty.List(cty.Bool),
-						Computed: true,
-					},
-					"optional_computed": {
-						Type:     cty.Map(cty.Bool),
-						Optional: true,
-					},
+					"optional":          {Type: cty.String, Optional: true},
+					"required":          {Type: cty.Number, Required: true},
+					"computed":          {Type: cty.List(cty.Bool), Computed: true},
+					"optional_computed": {Type: cty.Map(cty.Bool), Optional: true, Computed: true},
 				},
 			},
 			cty.ObjectWithOptionalAttrs(
@@ -161,7 +154,7 @@ func TestObjectImpliedType(t *testing.T) {
 					"computed":          cty.List(cty.Bool),
 					"optional_computed": cty.Map(cty.Bool),
 				},
-				[]string{"optional", "optional_computed"},
+				[]string{"optional", "computed", "optional_computed"},
 			),
 		},
 		"nested attributes": {
@@ -172,21 +165,42 @@ func TestObjectImpliedType(t *testing.T) {
 						NestedType: &Object{
 							Nesting: NestingSingle,
 							Attributes: map[string]*Attribute{
-								"optional": {
-									Type:     cty.String,
-									Optional: true,
-								},
-								"required": {
-									Type:     cty.Number,
-									Required: true,
-								},
-								"computed": {
-									Type:     cty.List(cty.Bool),
-									Computed: true,
-								},
-								"optional_computed": {
-									Type:     cty.Map(cty.Bool),
-									Optional: true,
+								"optional":          {Type: cty.String, Optional: true},
+								"required":          {Type: cty.Number, Required: true},
+								"computed":          {Type: cty.List(cty.Bool), Computed: true},
+								"optional_computed": {Type: cty.Map(cty.Bool), Optional: true, Computed: true},
+							},
+						},
+						Optional: true,
+					},
+				},
+			},
+			cty.ObjectWithOptionalAttrs(map[string]cty.Type{
+				"nested_type": cty.ObjectWithOptionalAttrs(map[string]cty.Type{
+					"optional":          cty.String,
+					"required":          cty.Number,
+					"computed":          cty.List(cty.Bool),
+					"optional_computed": cty.Map(cty.Bool),
+				}, []string{"optional", "computed", "optional_computed"}),
+			}, []string{"nested_type"}),
+		},
+		"nested object-type attributes": {
+			&Object{
+				Nesting: NestingSingle,
+				Attributes: map[string]*Attribute{
+					"nested_type": {
+						NestedType: &Object{
+							Nesting: NestingSingle,
+							Attributes: map[string]*Attribute{
+								"optional":          {Type: cty.String, Optional: true},
+								"required":          {Type: cty.Number, Required: true},
+								"computed":          {Type: cty.List(cty.Bool), Computed: true},
+								"optional_computed": {Type: cty.Map(cty.Bool), Optional: true, Computed: true},
+								"object": {
+									Type: cty.ObjectWithOptionalAttrs(map[string]cty.Type{
+										"optional": cty.String,
+										"required": cty.Number,
+									}, []string{"optional"}),
 								},
 							},
 						},
@@ -200,7 +214,8 @@ func TestObjectImpliedType(t *testing.T) {
 					"required":          cty.Number,
 					"computed":          cty.List(cty.Bool),
 					"optional_computed": cty.Map(cty.Bool),
-				}, []string{"optional", "optional_computed"}),
+					"object":            cty.ObjectWithOptionalAttrs(map[string]cty.Type{"optional": cty.String, "required": cty.Number}, []string{"optional"}),
+				}, []string{"optional", "computed", "optional_computed"}),
 			}, []string{"nested_type"}),
 		},
 		"NestingList": {
diff --git a/internal/plans/objchange/objchange_test.go b/internal/plans/objchange/objchange_test.go
index 3e9cc2055..8221f99bd 100644
--- a/internal/plans/objchange/objchange_test.go
+++ b/internal/plans/objchange/objchange_test.go
@@ -1457,7 +1457,7 @@ func TestProposedNew(t *testing.T) {
 						"computed":          cty.String,
 						"optional_computed": cty.String,
 						"required":          cty.String,
-					}, []string{"optional", "optional_computed"}),
+					}, []string{"computed", "optional", "optional_computed"}),
 				}))),
 			}),
 		},