diff --git a/terraform/ui_output.go b/terraform/ui_output.go
new file mode 100644
index 000000000..84427c63d
--- /dev/null
+++ b/terraform/ui_output.go
@@ -0,0 +1,7 @@
+package terraform
+
+// UIOutput is the interface that must be implemented to output
+// data to the end user.
+type UIOutput interface {
+	Output(string)
+}
diff --git a/terraform/ui_output_mock.go b/terraform/ui_output_mock.go
new file mode 100644
index 000000000..8e6ff82d7
--- /dev/null
+++ b/terraform/ui_output_mock.go
@@ -0,0 +1,16 @@
+package terraform
+
+// MockUIOutput is an implementation of UIOutput that can be used for tests.
+type MockUIOutput struct {
+	OutputCalled       bool
+	OutputMessage      string
+	OutputFn           func(string)
+}
+
+func (o *MockUIOutput) Output(v string) {
+	o.OutputCalled = true
+	o.OutputMessage= v
+	if o.OutputFn == nil {
+		o.OutputFn(v)
+	}
+}
diff --git a/terraform/ui_output_mock_test.go b/terraform/ui_output_mock_test.go
new file mode 100644
index 000000000..0a23c2e23
--- /dev/null
+++ b/terraform/ui_output_mock_test.go
@@ -0,0 +1,9 @@
+package terraform
+
+import (
+	"testing"
+)
+
+func TestMockUIOutput(t *testing.T) {
+	var _ UIOutput = new(MockUIOutput)
+}