diff --git a/server/server/commands.go b/server/server/commands.go
index a6a2397..5433fe0 100644
--- a/server/server/commands.go
+++ b/server/server/commands.go
@@ -18,12 +18,7 @@ func GetFile(c Client, path string) (int, error) {
 		return 0, ErrSlashNotAllowed
 	}
 
-	stack, ok := c.Stack().(*StringStack)
-	if !ok {
-		return 0, ErrStackCast
-	}
-
-	file, err := os.Open(MakePathFromStringStack(stack) + fileName)
+	file, err := os.Open(MakePathFromStringStack(c.Stack()) + fileName)
 	if err != nil {
 		log.Println(err.Error())
 		return 0, err
@@ -68,12 +63,8 @@ func sanitizeFilePath(path string) (string, bool) {
 
 // ListFiles list the files from path and sends them to the connection
 func ListFiles(c Client) error {
-	stack, ok := c.Stack().(*StringStack)
-	if !ok {
-		return ErrStackCast
-	}
 
-	files, err := ioutil.ReadDir(MakePathFromStringStack(stack))
+	files, err := ioutil.ReadDir(MakePathFromStringStack(c.Stack()))
 	if err != nil {
 		return err
 	}
@@ -110,17 +101,12 @@ func ChangeDirectoryCommand(c Client, directory string) error {
 		return ErrSlashNotAllowed
 	}
 
-	stack, ok := c.Stack().(*StringStack)
-	if !ok {
-		return ErrStackCast
-	}
-
 	if path == "." {
 		err = nil
 	} else if path == ".." {
-		err = ChangeDirectoryToPrevious(stack)
+		err = ChangeDirectoryToPrevious(c.Stack())
 	} else {
-		err = ChangeDirectory(stack, path)
+		err = ChangeDirectory(c.Stack(), path)
 	}
 
 	return err
diff --git a/server/server/connection.go b/server/server/connection.go
index c284485..b248138 100644
--- a/server/server/connection.go
+++ b/server/server/connection.go
@@ -18,7 +18,7 @@ type Client interface {
 	Connection() net.Conn        // Connection returns the connection stream.
 	SetConnection(conn net.Conn) // SetConnection sets the connection for the client.
 	Disconnect()                 // Disconnect closes the Client's connections and clears up resources.
-	Stack() Stack                // Returns the underlying String Stack.
+	Stack() *StringStack         // Returns the underlying String Stack.
 }
 
 // FTPClient represents a FTPClient connection, it holds a root cage and the underlying connection.
@@ -28,7 +28,7 @@ type FTPClient struct {
 }
 
 // Stack returns the root cage stack.
-func (c *FTPClient) Stack() Stack {
+func (c *FTPClient) Stack() *StringStack {
 	return c.rootCage
 }