diff --git a/cmd/gcd.go b/cmd/gcd.go
index 5d6a207..fa6a1af 100644
--- a/cmd/gcd.go
+++ b/cmd/gcd.go
@@ -24,12 +24,18 @@ import (
 	"github.com/spf13/cobra"
 )
 
+var extended bool
+
 func gcd(cmd *cobra.Command, args []string) {
 	var x big.Int
 	var y big.Int
 	var z big.Int
 	var w big.Int
 
+	if extended && len(args) > 2 {
+		log.Fatal("--extended unsupported for more than two values")
+	}
+
 	for _, s := range args {
 		_, ok := w.SetString(s, 10)
 		if !ok {
@@ -39,7 +45,11 @@ func gcd(cmd *cobra.Command, args []string) {
 		z.GCD(&x, &y, &z, &w)
 	}
 
-	fmt.Println(&z)
+	if extended {
+		fmt.Println(&z, &x, &y)
+	} else {
+		fmt.Println(&z)
+	}
 }
 
 // gcdCmd represents the gcd command
@@ -63,4 +73,6 @@ func init() {
 	// Cobra supports local flags which will only run when this command
 	// is called directly, e.g.:
 	// gcdCmd.Flags().BoolP("toggle", "t", false, "Help message for toggle")
+
+	gcdCmd.Flags().BoolVarP(&extended, "extended", "e", false, "also compute the Bezout coefficients")
 }