diff --git a/terraform/diff.go b/terraform/diff.go
index c50d3cedb3..d50ec5b10a 100644
--- a/terraform/diff.go
+++ b/terraform/diff.go
@@ -364,6 +364,12 @@ type InstanceDiff struct {
 	Destroy        bool
 	DestroyDeposed bool
 	DestroyTainted bool
+
+	// Meta is a simple K/V map that is stored in a diff and persisted to
+	// plans but otherwise is completely ignored by Terraform core. It is
+	// mean to be used for additional data a resource may want to pass through.
+	// The value here must only contain Go primitives and collections.
+	Meta map[string]interface{}
 }
 
 func (d *InstanceDiff) Lock()   { d.mu.Lock() }
diff --git a/terraform/plan_test.go b/terraform/plan_test.go
index 02331558a9..9515efbaaa 100644
--- a/terraform/plan_test.go
+++ b/terraform/plan_test.go
@@ -31,6 +31,10 @@ func TestReadWritePlan(t *testing.T) {
 									RequiresNew: true,
 								},
 							},
+
+							Meta: map[string]interface{}{
+								"foo": []interface{}{1, 2, 3},
+							},
 						},
 					},
 				},