diff --git a/terraform/context_test.go b/terraform/context_test.go
index faa7f75d8c..0188e7d951 100644
--- a/terraform/context_test.go
+++ b/terraform/context_test.go
@@ -4240,7 +4240,6 @@ func TestContext2Apply_output(t *testing.T) {
 	}
 }
 
-/*
 func TestContext2Apply_outputInvalid(t *testing.T) {
 	m := testModule(t, "apply-output-invalid")
 	p := testProvider("aws")
@@ -4261,7 +4260,6 @@ func TestContext2Apply_outputInvalid(t *testing.T) {
 		t.Fatalf("err: %s", err)
 	}
 }
-*/
 
 func TestContext2Apply_outputList(t *testing.T) {
 	m := testModule(t, "apply-output-list")
diff --git a/terraform/eval_output.go b/terraform/eval_output.go
index 849c2c90d6..1e03faf449 100644
--- a/terraform/eval_output.go
+++ b/terraform/eval_output.go
@@ -58,7 +58,7 @@ func (n *EvalWriteOutput) Eval(
 		valueRaw = list[0]
 	}
 	if _, ok := valueRaw.(string); !ok {
-		valueRaw = ""
+		return nil, fmt.Errorf("output %s is not a string", n.Name)
 	}
 
 	// Write the output