diff --git a/analysis/common_test.go b/analysis/common_test.go
index 3e6dfd27..940f15f8 100644
--- a/analysis/common_test.go
+++ b/analysis/common_test.go
@@ -144,7 +144,7 @@ func visitExprs(env *esc.Environment, visitor func(path string, x esc.Expr)) {
 		}
 	}
 
-	for _, key := range sortedKeys(env.Exprs) {
-		visit(env.Exprs[key], key)
+	for _, key := range sortedKeys(env.Exprs.Object) {
+		visit(env.Exprs.Object[key], key)
 	}
 }
diff --git a/analysis/traversal.go b/analysis/traversal.go
index bad2b507..1a2299a5 100644
--- a/analysis/traversal.go
+++ b/analysis/traversal.go
@@ -46,7 +46,7 @@ func (a *Analysis) ExpressionAtPos(pos esc.Pos) (*esc.Expr, bool) {
 // (nil, nil, false). The returned expression is the "smallest" expression that contains pos. The path to the given
 // expression is also returned.
 func (a *Analysis) expressionAtPos(pos esc.Pos) (*esc.Expr, []traverser, bool) {
-	for key, x := range a.env.Exprs {
+	for key, x := range a.env.Exprs.Object {
 		if x, where, ok := expressionAtPos(x, []traverser{newRootTraverser(key)}, pos); ok {
 			return x, where, true
 		}
diff --git a/ast/environment.go b/ast/environment.go
index 73f7bda6..37e2e0c6 100644
--- a/ast/environment.go
+++ b/ast/environment.go
@@ -196,7 +196,7 @@ type EnvironmentDecl struct {
 
 	Description *StringExpr
 	Imports     ImportListDecl
-	Values      PropertyMapDecl
+	Values      *ObjectExpr
 }
 
 func (d *EnvironmentDecl) Syntax() syntax.Node {
@@ -222,7 +222,7 @@ func (d *EnvironmentDecl) NewDiagnosticWriter(w io.Writer, width uint, color boo
 	return newDiagnosticWriter(w, fileMap, width, color)
 }
 
-func EnvironmentSyntax(node *syntax.ObjectNode, description *StringExpr, imports ImportListDecl, values PropertyMapDecl) *EnvironmentDecl {
+func EnvironmentSyntax(node *syntax.ObjectNode, description *StringExpr, imports ImportListDecl, values *ObjectExpr) *EnvironmentDecl {
 	return &EnvironmentDecl{
 		syntax:      node,
 		Description: description,
@@ -231,7 +231,7 @@ func EnvironmentSyntax(node *syntax.ObjectNode, description *StringExpr, imports
 	}
 }
 
-func Environment(description *StringExpr, imports ImportListDecl, values PropertyMapDecl) *EnvironmentDecl {
+func Environment(description *StringExpr, imports ImportListDecl, values *ObjectExpr) *EnvironmentDecl {
 	return EnvironmentSyntax(nil, description, imports, values)
 }
 
diff --git a/ast/expr.go b/ast/expr.go
index ef5155e3..7e0950b0 100644
--- a/ast/expr.go
+++ b/ast/expr.go
@@ -266,6 +266,13 @@ type ObjectExpr struct {
 	Entries []ObjectProperty
 }
 
+func (o *ObjectExpr) GetEntries() []ObjectProperty {
+	if o == nil {
+		return nil
+	}
+	return o.Entries
+}
+
 // An ObjectProperty represents an object property. Key must be a string.
 type ObjectProperty struct {
 	syntax syntax.ObjectPropertyDef
diff --git a/cmd/esc/cli/client/client_test.go b/cmd/esc/cli/client/client_test.go
index 368adfba..bda10a99 100644
--- a/cmd/esc/cli/client/client_test.go
+++ b/cmd/esc/cli/client/client_test.go
@@ -758,7 +758,9 @@ func TestCheckYAMLEnvironment(t *testing.T) {
 		yaml := []byte(`{"values":{"foo":"bar"}}`)
 
 		expected := &esc.Environment{
-			Exprs:      map[string]esc.Expr{"foo": {Literal: "bar"}},
+			Exprs: &esc.Expr{
+				Object: map[string]esc.Expr{"foo": {Literal: "bar"}},
+			},
 			Properties: map[string]esc.Value{"foo": esc.NewValue("bar")},
 			Schema:     schema.Record(schema.BuilderMap{"foo": schema.String().Const("bar")}).Schema(),
 		}
@@ -884,7 +886,9 @@ func TestOpenYAMLEnvironment(t *testing.T) {
 func TestGetOpenEnvironment(t *testing.T) {
 	t.Run("OK", func(t *testing.T) {
 		expected := &esc.Environment{
-			Exprs:      map[string]esc.Expr{"foo": {Literal: "bar"}},
+			Exprs: &esc.Expr{
+				Object: map[string]esc.Expr{"foo": {Literal: "bar"}},
+			},
 			Properties: map[string]esc.Value{"foo": esc.NewValue("bar")},
 			Schema:     schema.Record(schema.BuilderMap{"foo": schema.String().Const("bar")}).Schema(),
 		}
@@ -918,7 +922,9 @@ func TestGetOpenEnvironment(t *testing.T) {
 func TestGetAnonymousOpenEnvironment(t *testing.T) {
 	t.Run("OK", func(t *testing.T) {
 		expected := &esc.Environment{
-			Exprs:      map[string]esc.Expr{"foo": {Literal: "bar"}},
+			Exprs: &esc.Expr{
+				Object: map[string]esc.Expr{"foo": {Literal: "bar"}},
+			},
 			Properties: map[string]esc.Value{"foo": esc.NewValue("bar")},
 			Schema:     schema.Record(schema.BuilderMap{"foo": schema.String().Const("bar")}).Schema(),
 		}
diff --git a/cmd/esc/cli/env_get.go b/cmd/esc/cli/env_get.go
index 125d4e91..54c1559e 100644
--- a/cmd/esc/cli/env_get.go
+++ b/cmd/esc/cli/env_get.go
@@ -329,7 +329,7 @@ func (get *envGetCommand) getEnvironmentMember(
 	definitionYAML := ""
 	if valuesNode, ok := (encoding.YAMLSyntax{Node: &docNode}.Get(resource.PropertyPath{"values"})); ok {
 		if node, _ := (encoding.YAMLSyntax{Node: valuesNode}.Get(path)); node != nil {
-			expr, ok := getEnvExpr(esc.Expr{Object: env.Exprs}, path)
+			expr, ok := getEnvExpr(*env.Exprs, path)
 			if !ok {
 				return nil, fmt.Errorf("internal error: no expr for path %v", path)
 			}
diff --git a/environment.go b/environment.go
index 551314ab..1b0f7d5c 100644
--- a/environment.go
+++ b/environment.go
@@ -164,8 +164,8 @@ type EvaluatedExecutionContext struct {
 
 // An Environment contains the result of evaluating an environment definition.
 type Environment struct {
-	// Exprs contains the AST for each expression in the environment definition.
-	Exprs map[string]Expr `json:"exprs,omitempty"`
+	// Exprs contains the AST for the root object expression.
+	Exprs *Expr `json:"exprs,omitempty"`
 
 	// Properties contains the detailed values produced by the environment.
 	Properties map[string]Value `json:"properties,omitempty"`
diff --git a/eval/eval.go b/eval/eval.go
index e6372ebf..6a864546 100644
--- a/eval/eval.go
+++ b/eval/eval.go
@@ -163,8 +163,9 @@ func evalEnvironment(
 	envProperties, exportDiags := v.export(name)
 	diags.Extend(exportDiags...)
 
+	rootExpr := ec.root.export(name)
 	return &esc.Environment{
-		Exprs:            ec.root.export(name).Object,
+		Exprs:            &rootExpr,
 		Properties:       envProperties.Value.(map[string]esc.Value),
 		Schema:           s,
 		ExecutionContext: executionContext,
@@ -437,7 +438,7 @@ func (e *evalContext) evaluate() (*value, syntax.Diagnostics) {
 	e.root = &expr{
 		path: "<" + e.name + ">",
 		repr: &objectExpr{
-			node:       ast.Object(),
+			node:       e.env.Values,
 			properties: properties,
 		},
 		base: e.base,