diff --git a/vendor/github.com/masterzen/winrm/client.go b/vendor/github.com/masterzen/winrm/client.go
index 732dd61cb..c19515194 100644
--- a/vendor/github.com/masterzen/winrm/client.go
+++ b/vendor/github.com/masterzen/winrm/client.go
@@ -152,10 +152,20 @@ func (c *Client) RunWithString(command string, stdin string) (string, string, in
 	}
 
 	var outWriter, errWriter bytes.Buffer
-	go io.Copy(&outWriter, cmd.Stdout)
-	go io.Copy(&errWriter, cmd.Stderr)
+	var wg sync.WaitGroup
+	wg.Add(2)
+	go func() {
+		defer wg.Done()
+		io.Copy(&outWriter, cmd.Stdout)
+	}()
+
+	go func() {
+		defer wg.Done()
+		io.Copy(&errWriter, cmd.Stderr)
+	}()
 
 	cmd.Wait()
+	wg.Wait()
 
 	return outWriter.String(), errWriter.String(), cmd.ExitCode(), cmd.err
 }
@@ -176,11 +186,24 @@ func (c Client) RunWithInput(command string, stdout, stderr io.Writer, stdin io.
 		return 1, err
 	}
 
-	go io.Copy(cmd.Stdin, stdin)
-	go io.Copy(stdout, cmd.Stdout)
-	go io.Copy(stderr, cmd.Stderr)
+	var wg sync.WaitGroup
+	wg.Add(3)
+
+	go func() {
+		defer wg.Done()
+		io.Copy(cmd.Stdin, stdin)
+	}()
+	go func() {
+		defer wg.Done()
+		io.Copy(stdout, cmd.Stdout)
+	}()
+	go func() {
+		defer wg.Done()
+		io.Copy(stderr, cmd.Stderr)
+	}()
 
 	cmd.Wait()
+	wg.Wait()
 
 	return cmd.ExitCode(), cmd.err
 
diff --git a/vendor/vendor.json b/vendor/vendor.json
index 1f08d096b..f3e751ef9 100644
--- a/vendor/vendor.json
+++ b/vendor/vendor.json
@@ -988,16 +988,16 @@
 			"revision": "95ba30457eb1121fa27753627c774c7cd4e90083"
 		},
 		{
-			"checksumSHA1": "8z5kCCFRsBkhXic9jxxeIV3bBn8=",
+			"checksumSHA1": "dVQEUn5TxdIAXczK7rh6qUrq44Q=",
 			"path": "github.com/masterzen/winrm",
-			"revision": "a2df6b1315e6fd5885eb15c67ed259e85854125f",
-			"revisionTime": "2017-08-14T13:39:27Z"
+			"revision": "7e40f93ae939004a1ef3bd5ff5c88c756ee762bb",
+			"revisionTime": "2018-02-24T16:03:50Z"
 		},
 		{
 			"checksumSHA1": "XFSXma+KmkhkIPsh4dTd/eyja5s=",
 			"path": "github.com/masterzen/winrm/soap",
-			"revision": "a2df6b1315e6fd5885eb15c67ed259e85854125f",
-			"revisionTime": "2017-08-14T13:39:27Z"
+			"revision": "7e40f93ae939004a1ef3bd5ff5c88c756ee762bb",
+			"revisionTime": "2018-02-24T16:03:50Z"
 		},
 		{
 			"checksumSHA1": "NkbetqlpWBi3gP08JDneC+axTKw=",