diff --git a/data/int.go b/data/int.go
new file mode 100644
index 0000000..1a5b191
--- /dev/null
+++ b/data/int.go
@@ -0,0 +1,14 @@
+package data
+
+import "time"
+
+const (
+	startupTimeout  = 200 * time.Millisecond
+	minAwaitTimeout = 100 * time.Millisecond
+	maxAwaitTimeout = 1 * time.Second
+)
+
+type InteractiveShell interface {
+	init() error
+	execute() (string, error)
+}
diff --git a/data/int_shell.go b/data/int_basic.go
similarity index 95%
rename from data/int_shell.go
rename to data/int_basic.go
index 86d934c..fb8c31a 100644
--- a/data/int_shell.go
+++ b/data/int_basic.go
@@ -25,7 +25,11 @@ func (s *BasicInteractiveShell) init() error {
 
 	cmd := exec.Command("sh", "-c", s.item.initScripts[0])
 	enrichEnvVariables(cmd, s.variables)
-	cmd.Wait()
+
+	err := cmd.Wait()
+	if err != nil {
+		return err
+	}
 
 	stdout, err := cmd.StdoutPipe()
 	if err != nil {
@@ -78,6 +82,10 @@ func (s *BasicInteractiveShell) init() error {
 
 func (s *BasicInteractiveShell) execute() (string, error) {
 
+	if s.stdin == nil {
+		return "", nil
+	}
+
 	_, err := io.WriteString(s.stdin, fmt.Sprintf(" %s\n", s.item.sampleScript))
 	if err != nil {
 		s.errCount++
diff --git a/data/int_pty.go b/data/int_pty.go
index 5585c3f..09e6b05 100644
--- a/data/int_pty.go
+++ b/data/int_pty.go
@@ -12,15 +12,6 @@ import (
 	"time"
 )
 
-const (
-	startupTimeout  = 200 * time.Millisecond
-	minAwaitTimeout = 100 * time.Millisecond
-	maxAwaitTimeout = 1 * time.Second
-)
-
-/**
- * Experimental
- */
 type PtyInteractiveShell struct {
 	item      *Item
 	variables []string
diff --git a/data/int_pty_windows.go b/data/int_pty_windows.go
new file mode 100644
index 0000000..8a3b243
--- /dev/null
+++ b/data/int_pty_windows.go
@@ -0,0 +1,20 @@
+package data
+
+import (
+	"errors"
+	"time"
+)
+
+type PtyInteractiveShell struct {
+	item      *Item
+	variables []string
+	timeout   time.Duration
+}
+
+func (s *PtyInteractiveShell) init() error {
+	return errors.New("PTY mode is not supported on Windows")
+}
+
+func (s *PtyInteractiveShell) execute() (string, error) {
+	return "", errors.New("PTY mode is not supported on Windows")
+}
diff --git a/data/item.go b/data/item.go
index d692cf0..b637110 100644
--- a/data/item.go
+++ b/data/item.go
@@ -18,8 +18,8 @@ type Item struct {
 	color           *ui.Color
 	rateMs          int
 	pty             bool
-	basicShell      *BasicInteractiveShell
-	ptyShell        *PtyInteractiveShell
+	basicShell      InteractiveShell
+	ptyShell        InteractiveShell
 }
 
 func NewItems(cfgs []config.Item, rateMs int) []*Item {