diff --git a/command.go b/command.go
index 10d66b1..7dd6b52 100644
--- a/command.go
+++ b/command.go
@@ -100,6 +100,10 @@ func (c *Command) With(opts ...Option) *Command {
 
 // Run run command with input and output.
 func (c *Command) Run(ctx context.Context, in input.Input, out output.Output) error {
+	if c.Execute == nil {
+		return fmt.Errorf("%w", ErrExecuteNil)
+	}
+
 	if c.Handle != nil {
 		return c.Handle(ctx, in, out, c.Execute)
 	}
diff --git a/command_test.go b/command_test.go
index 62e593e..7579fbe 100644
--- a/command_test.go
+++ b/command_test.go
@@ -2,6 +2,7 @@ package console_test
 
 import (
 	"context"
+	"errors"
 	"strings"
 	"sync/atomic"
 	"testing"
@@ -125,3 +126,21 @@ func TestChainHandle(t *testing.T) {
 		}
 	}
 }
+
+func TestRunEmptyExecute(t *testing.T) {
+	t.Parallel()
+
+	ctx := context.Background()
+	empty := console.Command{
+		Name: "empty",
+	}
+	in := &input.Array{
+		Map: input.Map{},
+	}
+	out := output.Stdout()
+
+	err := empty.Run(ctx, in, out)
+	if !errors.Is(err, console.ErrExecuteNil) {
+		t.Fatalf("expected: %v, got: %v ", console.ErrExecuteNil, err)
+	}
+}
diff --git a/error.go b/error.go
new file mode 100644
index 0000000..6e29f34
--- /dev/null
+++ b/error.go
@@ -0,0 +1,31 @@
+package console
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+)
+
+var (
+	ErrNotFound         = errors.New("command not found")
+	ErrCommandNil       = errors.New("console: Register command is nil")
+	ErrExecuteNil       = errors.New("console: execute is nil")
+	ErrCommandDuplicate = errors.New("console: duplicate command")
+)
+
+type AlternativesError struct {
+	Alt []string
+	Err error
+}
+
+func (e AlternativesError) Error() string {
+	return fmt.Sprintf("%s, alternatives: [%s]", e.Err, strings.Join(e.Alt, ","))
+}
+
+func (e AlternativesError) Is(err error) bool {
+	return errors.Is(e.Err, err)
+}
+
+func (e AlternativesError) Unwrap() error {
+	return e.Err
+}
diff --git a/register.go b/register.go
index 8cddd5d..7ed1a8a 100644
--- a/register.go
+++ b/register.go
@@ -5,7 +5,6 @@ import (
 	"fmt"
 	"regexp"
 	"sort"
-	"strings"
 	"sync"
 )
 
@@ -14,12 +13,6 @@ const (
 	CommandList = "list"
 )
 
-var (
-	ErrNotFound         = errors.New("command not found")
-	ErrCommandNil       = errors.New("console: Register command is nil")
-	ErrCommandDuplicate = errors.New("console: duplicate command")
-)
-
 //nolint:gochecknoglobals
 var (
 	commandsMu  sync.RWMutex
@@ -27,27 +20,6 @@ var (
 	findCommand = regexp.MustCompile("([^:]+|)")
 )
 
-type AlternativesError struct {
-	alt []string
-	err error
-}
-
-func (e AlternativesError) Error() string {
-	return fmt.Sprintf("%s, alternatives: [%s]", e.err, strings.Join(e.alt, ","))
-}
-
-func (e AlternativesError) Is(err error) bool {
-	return errors.Is(e.err, err)
-}
-
-func (e AlternativesError) Unwrap() error {
-	return e.err
-}
-
-func (e AlternativesError) Alternatives() []string {
-	return e.alt
-}
-
 // MustRegister register command or panic if err.
 func MustRegister(cmd *Command) {
 	if err := Register(cmd); err != nil {
@@ -134,7 +106,7 @@ func Find(name string) (*Command, error) {
 			names[i] = findCommands[i].Name
 		}
 
-		return nil, AlternativesError{alt: names, err: ErrNotFound}
+		return nil, AlternativesError{Alt: names, Err: ErrNotFound}
 	}
 
 	return nil, ErrNotFound