diff --git a/helper/resource/testing.go b/helper/resource/testing.go
index 205547eff..8db38a77c 100644
--- a/helper/resource/testing.go
+++ b/helper/resource/testing.go
@@ -186,6 +186,10 @@ type TestCheckFunc func(*terraform.State) error
 // ImportStateCheckFunc is the check function for ImportState tests
 type ImportStateCheckFunc func([]*terraform.InstanceState) error
 
+// ImportStateIdFunc is an ID generation function to help with complex ID
+// generation for ImportState tests.
+type ImportStateIdFunc func(*terraform.State) (string, error)
+
 // TestCase is a single acceptance test case used to test the apply/destroy
 // lifecycle of a resource in a specific configuration.
 //
@@ -333,6 +337,12 @@ type TestStep struct {
 	// the unset ImportStateId field.
 	ImportStateIdPrefix string
 
+	// ImportStateIdFunc is a function that can be used to dynamically generate
+	// the ID for the ImportState tests. It is sent the state, which can be
+	// checked to derive the attributes necessary and generate the string in the
+	// desired format.
+	ImportStateIdFunc ImportStateIdFunc
+
 	// ImportStateCheck checks the results of ImportState. It should be
 	// used to verify that the resulting value of ImportState has the
 	// proper resources, IDs, and attributes.
diff --git a/helper/resource/testing_import_state.go b/helper/resource/testing_import_state.go
index 28ad10526..94fef3cfb 100644
--- a/helper/resource/testing_import_state.go
+++ b/helper/resource/testing_import_state.go
@@ -16,15 +16,24 @@ func testStepImportState(
 	state *terraform.State,
 	step TestStep) (*terraform.State, error) {
 	// Determine the ID to import
-	importId := step.ImportStateId
-	if importId == "" {
+	var importId string
+	switch {
+	case step.ImportStateIdFunc != nil:
+		var err error
+		importId, err = step.ImportStateIdFunc(state)
+		if err != nil {
+			return state, err
+		}
+	case step.ImportStateId != "":
+		importId = step.ImportStateId
+	default:
 		resource, err := testResource(step, state)
 		if err != nil {
 			return state, err
 		}
-
 		importId = resource.Primary.ID
 	}
+
 	importPrefix := step.ImportStateIdPrefix
 	if importPrefix != "" {
 		importId = fmt.Sprintf("%s%s", importPrefix, importId)
diff --git a/helper/resource/testing_import_state_test.go b/helper/resource/testing_import_state_test.go
index 8ef8323ba..c91355108 100644
--- a/helper/resource/testing_import_state_test.go
+++ b/helper/resource/testing_import_state_test.go
@@ -388,3 +388,61 @@ func TestTest_importStateVerifyFail(t *testing.T) {
 		t.Fatalf("test should fail")
 	}
 }
+
+func TestTest_importStateIdFunc(t *testing.T) {
+	mp := testProvider()
+	mp.ImportStateFn = func(
+		info *terraform.InstanceInfo, id string) ([]*terraform.InstanceState, error) {
+		if id != "foo:bar" {
+			return nil, fmt.Errorf("bad import ID: %s", id)
+		}
+
+		return []*terraform.InstanceState{
+			{
+				ID:        "foo",
+				Ephemeral: terraform.EphemeralState{Type: "test_instance"},
+			},
+		}, nil
+	}
+
+	mp.RefreshFn = func(
+		i *terraform.InstanceInfo,
+		s *terraform.InstanceState) (*terraform.InstanceState, error) {
+		return s, nil
+	}
+
+	checked := false
+	checkFn := func(s []*terraform.InstanceState) error {
+		checked = true
+
+		if s[0].ID != "foo" {
+			return fmt.Errorf("bad: %#v", s)
+		}
+
+		return nil
+	}
+
+	mt := new(mockT)
+	Test(mt, TestCase{
+		Providers: map[string]terraform.ResourceProvider{
+			"test": mp,
+		},
+
+		Steps: []TestStep{
+			TestStep{
+				Config:            testConfigStrProvider,
+				ResourceName:      "test_instance.foo",
+				ImportState:       true,
+				ImportStateIdFunc: func(*terraform.State) (string, error) { return "foo:bar", nil },
+				ImportStateCheck:  checkFn,
+			},
+		},
+	})
+
+	if mt.failed() {
+		t.Fatalf("test failed: %s", mt.failMessage())
+	}
+	if !checked {
+		t.Fatal("didn't call check")
+	}
+}