diff --git a/provisioner/powershell/provisioner.go b/provisioner/powershell/provisioner.go
index 0c2454d0d..b31781d88 100644
--- a/provisioner/powershell/provisioner.go
+++ b/provisioner/powershell/provisioner.go
@@ -294,7 +294,9 @@ func (p *Provisioner) Provision(ui packer.Ui, comm packer.Communicator) error {
 			}
 		}
 		if !validExitCode {
-			return fmt.Errorf("Script exited with non-zero exit status: %d. Allowed exit codes are: %s", cmd.ExitStatus, p.config.ValidExitCodes)
+			return fmt.Errorf(
+				"Script exited with non-zero exit status: %d. Allowed exit codes are: %v",
+				cmd.ExitStatus, p.config.ValidExitCodes)
 		}
 	}
 
diff --git a/provisioner/windows-restart/provisioner_test.go b/provisioner/windows-restart/provisioner_test.go
index f0f2766e3..d2a54d274 100644
--- a/provisioner/windows-restart/provisioner_test.go
+++ b/provisioner/windows-restart/provisioner_test.go
@@ -234,7 +234,7 @@ func TestProvision_waitForCommunicator(t *testing.T) {
 	err := waitForCommunicator(p)
 
 	if err != nil {
-		t.Fatal("should not have error, got: %s", err.Error())
+		t.Fatalf("should not have error, got: %s", err.Error())
 	}
 
 	expectedCommand := DefaultRestartCheckCommand