1 files changed, 5 insertions, 0 deletions

diff --git a/vendor/github.com/hashicorp/terraform/terraform/ui_output_mock.go b/vendor/github.com/hashicorp/terraform/terraform/ui_output_mock.go
index 7852bc4..d828c92 100644
--- a/vendor/github.com/hashicorp/terraform/terraform/ui_output_mock.go
+++ b/vendor/github.com/hashicorp/terraform/terraform/ui_output_mock.go
@@ -1,13 +1,18 @@
 package terraform
 
+import "sync"
+
 // MockUIOutput is an implementation of UIOutput that can be used for tests.
 type MockUIOutput struct {
+        sync.Mutex
         OutputCalled  bool
         OutputMessage string
         OutputFn      func(string)
 }
 
 func (o *MockUIOutput) Output(v string) {
+        o.Lock()
+        defer o.Unlock()
         o.OutputCalled = true
         o.OutputMessage = v
         if o.OutputFn != nil {