diff --git a/README.md b/README.md
index 47404e5..bf1b72a 100644
--- a/README.md
+++ b/README.md
@@ -37,7 +37,7 @@ v0.0.3
 v0.0.4
 v0.0.5
 
-❯ tagli increment -t v0.0.5 -v patch                  
+❯ tagli increment -t v0.0.5 --type patch                  
 Tag v0.0.6 was created
 
 ❯ git tag -l                                                   
diff --git a/cmd/increment.go b/cmd/increment.go
index 9c9fbbf..45b8e5e 100644
--- a/cmd/increment.go
+++ b/cmd/increment.go
@@ -25,17 +25,17 @@ var incrementCmd = &cobra.Command{
 			os.Exit(1)
 		}
 
-		version, err := cmd.Flags().GetString("version")
+		versionType, err := cmd.Flags().GetString("type")
 		if err != nil {
-			fmt.Println("Failed to parse --version option")
+			fmt.Println("Failed to parse --type option")
 			os.Exit(1)
 		}
-		incrementGitTag(tagName, incrementValue, version)
+		incrementGitTag(tagName, incrementValue, versionType)
 	},
 	Short: "Increment a tag of Git repository",
 }
 
-func incrementGitTag(tagName string, incrementValue int, version string) {
+func incrementGitTag(tagName string, incrementValue int, versionType string) {
 	repo, err := git.PlainOpen(RepositoryPath)
 	head, err := repo.Head()
 	if err != nil {
@@ -43,7 +43,12 @@ func incrementGitTag(tagName string, incrementValue int, version string) {
 		os.Exit(1)
 	}
 
-	incrementTag := increment(tagName, incrementValue, version)
+	incrementTag, err := incrementVersion(tagName, incrementValue, versionType)
+	if err != nil {
+		fmt.Printf("increment version error: %s", err)
+		os.Exit(1)
+	}
+
 	_, err = repo.CreateTag(incrementTag, head.Hash(), nil)
 	if err != nil {
 		fmt.Printf("create tag error: %s", err)
@@ -53,25 +58,22 @@ func incrementGitTag(tagName string, incrementValue int, version string) {
 	os.Exit(0)
 }
 
-func increment(tagName string, incrementValue int, version string) string {
+func incrementVersion(tagName string, incrementValue int, versionType string) (string, error) {
 	versionObj, err := semver.NewVersion(tagName)
 	if err != nil {
-		fmt.Printf("create tag error: %s", err)
-		os.Exit(1)
+		return "", fmt.Errorf("Invalid version: %s", tagName)
 	}
 
-	switch version {
+	switch versionType {
 	case "major":
-		return incrementMajor(versionObj, incrementValue)
+		return incrementMajor(versionObj, incrementValue), nil
 	case "minor":
-		return incrementMinor(versionObj, incrementValue)
+		return incrementMinor(versionObj, incrementValue), nil
 	case "patch":
-		return incrementPatch(versionObj, incrementValue)
+		return incrementPatch(versionObj, incrementValue), nil
 	default:
-		fmt.Println("Invalid version")
-		os.Exit(1)
+		return "", fmt.Errorf("Invalid version type: %s", versionType)
 	}
-	return ""
 }
 
 func containsVprefix(tagName string) bool {
@@ -79,7 +81,10 @@ func containsVprefix(tagName string) bool {
 }
 
 func incrementMajor(version *semver.Version, incrementValue int) string {
-	m := version.IncMajor()
+	var m *semver.Version = version
+	for i := 0; i < incrementValue; i++ {
+		*m = version.IncMajor()
+	}
 	if containsVprefix(version.Original()) {
 		return "v" + m.String()
 	}
@@ -87,7 +92,10 @@ func incrementMajor(version *semver.Version, incrementValue int) string {
 }
 
 func incrementMinor(version *semver.Version, incrementValue int) string {
-	m := version.IncMinor()
+	var m *semver.Version = version
+	for i := 0; i < incrementValue; i++ {
+		*m = version.IncMinor()
+	}
 	if containsVprefix(version.Original()) {
 		return "v" + m.String()
 	}
@@ -95,7 +103,10 @@ func incrementMinor(version *semver.Version, incrementValue int) string {
 }
 
 func incrementPatch(version *semver.Version, incrementValue int) string {
-	m := version.IncPatch()
+	var m *semver.Version = version
+	for i := 0; i < incrementValue; i++ {
+		*m = version.IncPatch()
+	}
 	if containsVprefix(version.Original()) {
 		return "v" + m.String()
 	}
@@ -106,9 +117,9 @@ func init() {
 	incrementCmd.Flags().StringP("tag", "t", "", "tag name")
 	incrementCmd.Flags().IntP("increment", "i", 1, "increment value")
 	incrementCmd.Flags().StringP("repository", "r", ".", "repository path")
-	incrementCmd.Flags().StringP("version", "v", "", "version (patch, minor, major))")
+	incrementCmd.Flags().StringP("type", "", "", "version type (patch, minor, major))")
 
 	incrementCmd.MarkFlagRequired("tag")
-	incrementCmd.MarkFlagRequired("version")
+	incrementCmd.MarkFlagRequired("type")
 	rootCmd.AddCommand(incrementCmd)
 }
diff --git a/cmd/increment_test.go b/cmd/increment_test.go
new file mode 100644
index 0000000..95e49b1
--- /dev/null
+++ b/cmd/increment_test.go
@@ -0,0 +1,82 @@
+package cmd
+
+import (
+	"testing"
+)
+
+func TestIncrementVersion(t *testing.T) {
+	testCases := []struct {
+		name            string
+		currentVersion  string
+		incrementValue  int
+		versionType     string
+		expectedVersion string
+		expectedError   bool
+	}{
+		{
+			name:            "major delta",
+			currentVersion:  "1.0.0",
+			incrementValue:  1,
+			versionType:     "major",
+			expectedVersion: "2.0.0",
+		},
+		{
+			name:            "minor delta",
+			currentVersion:  "1.1.0",
+			incrementValue:  1,
+			versionType:     "minor",
+			expectedVersion: "1.2.0",
+		},
+		{
+			name:            "patch delta",
+			currentVersion:  "1.0.1",
+			incrementValue:  1,
+			versionType:     "patch",
+			expectedVersion: "1.0.2",
+		},
+		{
+			name:            "major 2 delta",
+			currentVersion:  "1.2.0",
+			incrementValue:  2,
+			versionType:     "major",
+			expectedVersion: "3.0.0",
+		},
+		{
+			name:            "minor 2 delta",
+			currentVersion:  "1.2.0",
+			incrementValue:  2,
+			versionType:     "minor",
+			expectedVersion: "1.4.0",
+		},
+		{
+			name:            "patch 2 delta",
+			currentVersion:  "1.2.0",
+			incrementValue:  2,
+			versionType:     "patch",
+			expectedVersion: "1.2.2",
+		},
+		{
+			name:            "invalid version type",
+			currentVersion:  "1.2",
+			incrementValue:  2,
+			versionType:     "dummy",
+			expectedVersion: "",
+			expectedError:   true,
+		},
+	}
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			got, err := incrementVersion(tc.currentVersion, tc.incrementValue, tc.versionType)
+			if got != tc.expectedVersion {
+				t.Errorf("expected %v: got %v", tc.expectedVersion, got)
+			}
+			if (err != nil) != tc.expectedError {
+				if tc.expectedError {
+					t.Errorf("expected an error but got no error")
+				} else {
+					t.Errorf("expected no error but got an error: %v", err)
+				}
+			}
+		})
+	}
+}