diff --git a/terraform/graph_config_node.go b/terraform/graph_config_node.go
index 3e21e8052..55c90df8b 100644
--- a/terraform/graph_config_node.go
+++ b/terraform/graph_config_node.go
@@ -94,6 +94,11 @@ func (n *GraphNodeConfigOutput) EvalTree() EvalNode {
 	}
 }
 
+// GraphNodeProxy impl.
+func (n *GraphNodeConfigOutput) Proxy() bool {
+	return true
+}
+
 // GraphNodeConfigProvider represents a configured provider within the
 // configuration graph. These are only immediately in the graph when an
 // explicit `provider` configuration block is in the configuration.
diff --git a/terraform/graph_config_node_module.go b/terraform/graph_config_node_module.go
index 48c1b6a4f..15fa29ace 100644
--- a/terraform/graph_config_node_module.go
+++ b/terraform/graph_config_node_module.go
@@ -283,6 +283,15 @@ func (n *graphNodeModuleFlatWrap) DependentOn() []string {
 	return result
 }
 
+func (n *graphNodeModuleFlatWrap) Proxy() bool {
+	pn, ok := n.graphNodeModuleWrappable.(GraphNodeProxy)
+	if !ok {
+		return false
+	}
+
+	return pn.Proxy()
+}
+
 func (n *graphNodeModuleFlatWrap) prefixList(result []string, prefix string) {
 	for i, v := range result {
 		result[i] = fmt.Sprintf("%s.%s", prefix, v)
diff --git a/terraform/graph_config_node_test.go b/terraform/graph_config_node_test.go
index b297c6c13..977f5c25f 100644
--- a/terraform/graph_config_node_test.go
+++ b/terraform/graph_config_node_test.go
@@ -13,6 +13,7 @@ func TestGraphNodeConfigOutput_impl(t *testing.T) {
 	var _ dag.NamedVertex = new(GraphNodeConfigOutput)
 	var _ graphNodeConfig = new(GraphNodeConfigOutput)
 	var _ GraphNodeOutput = new(GraphNodeConfigOutput)
+	var _ GraphNodeProxy = new(GraphNodeConfigOutput)
 }
 
 func TestGraphNodeConfigProvider_impl(t *testing.T) {
@@ -113,4 +114,5 @@ func TestGraphNodeConfigVariable_impl(t *testing.T) {
 	var _ dag.NamedVertex = new(GraphNodeConfigVariable)
 	var _ graphNodeConfig = new(GraphNodeConfigVariable)
 	var _ GraphNodeVariable = new(GraphNodeConfigVariable)
+	var _ GraphNodeProxy = new(GraphNodeConfigVariable)
 }
diff --git a/terraform/graph_config_node_variable.go b/terraform/graph_config_node_variable.go
index b6e539006..964b7b006 100644
--- a/terraform/graph_config_node_variable.go
+++ b/terraform/graph_config_node_variable.go
@@ -61,3 +61,8 @@ func (n *GraphNodeConfigVariable) VariableName() string {
 func (n *GraphNodeConfigVariable) SetVariableValue(v *config.RawConfig) {
 	n.Value = v
 }
+
+// GraphNodeProxy impl.
+func (n *GraphNodeConfigVariable) Proxy() bool {
+	return true
+}
diff --git a/terraform/transform_flatten_test.go b/terraform/transform_flatten_test.go
index eddad8897..749102469 100644
--- a/terraform/transform_flatten_test.go
+++ b/terraform/transform_flatten_test.go
@@ -35,6 +35,37 @@ func TestFlattenTransformer(t *testing.T) {
 	}
 }
 
+func TestFlattenTransformer_withProxy(t *testing.T) {
+	mod := testModule(t, "transform-flatten")
+
+	var b BasicGraphBuilder
+	b = BasicGraphBuilder{
+		Steps: []GraphTransformer{
+			&ConfigTransformer{Module: mod},
+			&VertexTransformer{
+				Transforms: []GraphVertexTransformer{
+					&ExpandTransform{
+						Builder: &b,
+					},
+				},
+			},
+			&FlattenTransformer{},
+			&ProxyTransformer{},
+		},
+	}
+
+	g, err := b.Build(rootModulePath)
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	actual := strings.TrimSpace(g.String())
+	expected := strings.TrimSpace(testTransformFlattenProxyStr)
+	if actual != expected {
+		t.Fatalf("bad:\n\n%s", actual)
+	}
+}
+
 const testTransformFlattenStr = `
 aws_instance.parent
 aws_instance.parent-output
@@ -46,3 +77,17 @@ module.child.output.output
 module.child.var.var
   aws_instance.parent
 `
+
+const testTransformFlattenProxyStr = `
+aws_instance.parent
+aws_instance.parent-output
+  module.child.aws_instance.child
+  module.child.output.output
+module.child.aws_instance.child
+  aws_instance.parent
+  module.child.var.var
+module.child.output.output
+  module.child.aws_instance.child
+module.child.var.var
+  aws_instance.parent
+`