diff --git a/cmd_regexp.go b/cmd_regexp.go
index 5e73e4d..a9d5194 100644
--- a/cmd_regexp.go
+++ b/cmd_regexp.go
@@ -12,6 +12,7 @@ import (
 type cmdRegexp struct{}
 
 func (c *cmdRegexp) run(ctx context.Context, argv []string, outStream io.Writer, errStream io.Writer) error {
+	// FIXME:
 	if len(argv) < 3 {
 		return fmt.Errorf("not enough arguments")
 	}
@@ -25,7 +26,7 @@ func (c *cmdRegexp) run(ctx context.Context, argv []string, outStream io.Writer,
 		return fmt.Errorf("invalid index: %s", err)
 	}
 
-	str, err := getOut(pkgs, total, idx)
+	str, err := getOut(pkgs, detectTags(argv), total, idx)
 	if err != nil {
 		return err
 	}
@@ -33,14 +34,14 @@ func (c *cmdRegexp) run(ctx context.Context, argv []string, outStream io.Writer,
 	return err
 }
 
-func getOut(pkgs []string, total, idx int) (string, error) {
+func getOut(pkgs []string, tags string, total, idx int) (string, error) {
 	if total < 1 {
 		return "", fmt.Errorf("invalid total: %d", total)
 	}
 	if idx >= total {
 		return "", fmt.Errorf("index shoud be between 0 to total-1, but: %d (total:%d)", idx, total)
 	}
-	testLists, err := getTestListsFromPkgs(pkgs)
+	testLists, err := getTestListsFromPkgs(pkgs, tags)
 	if err != nil {
 		return "", err
 	}
diff --git a/gotesplit.go b/gotesplit.go
index b38efdb..766224b 100644
--- a/gotesplit.go
+++ b/gotesplit.go
@@ -9,6 +9,7 @@ import (
 	"log"
 	"os"
 	"os/exec"
+	"regexp"
 	"sort"
 	"strings"
 )
@@ -59,8 +60,12 @@ Options:
 	return run(ctx, *total, *index, *junitDir, argv, outStream, errStream)
 }
 
-func getTestListsFromPkgs(pkgs []string) ([]testList, error) {
-	args := append([]string{"test", "-list", "."}, pkgs...)
+func getTestListsFromPkgs(pkgs []string, tags string) ([]testList, error) {
+	args := []string{"test", "-list"}
+	if tags != "" {
+		args = append(args, tags)
+	}
+	args = append(append(args, "."), pkgs...)
 	buf := &bytes.Buffer{}
 	c := exec.Command("go", args...)
 	c.Stdout = buf
@@ -72,6 +77,24 @@ func getTestListsFromPkgs(pkgs []string) ([]testList, error) {
 	return getTestLists(buf.String()), nil
 }
 
+var tagsReg = regexp.MustCompile(`^--?tags(=.*)?$`)
+
+func detectTags(argv []string) string {
+	l := len(argv)
+	for i := 0; i < l; i++ {
+		tags := argv[i]
+		m := tagsReg.FindStringSubmatch(tags)
+		if len(m) < 2 {
+			continue
+		}
+		if m[1] == "" && i+1 < l {
+			tags += "=" + argv[i+1]
+		}
+		return tags
+	}
+	return ""
+}
+
 type testList struct {
 	pkg  string
 	list []string
diff --git a/gotesplit_test.go b/gotesplit_test.go
index d07effc..2524f07 100644
--- a/gotesplit_test.go
+++ b/gotesplit_test.go
@@ -102,3 +102,24 @@ ok      github.com/x-motemen/ghq/logger 0.106s`
 		t.Errorf("expect: %#v\ngot: %#v", expect, got)
 	}
 }
+
+func TestDetectTags(t *testing.T) {
+	testCases := []struct {
+		input  []string
+		expect string
+	}{
+		{[]string{"aa", "bb"}, ""},
+		{[]string{"aa", "-tags", "bb"}, "-tags=bb"},
+		{[]string{"aa", "--tags=ccc", "bb"}, "--tags=ccc"},
+		{[]string{"aa", "-tags"}, "-tags"},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.expect, func(t *testing.T) {
+			out := detectTags(tc.input)
+			if out != tc.expect {
+				t.Errorf("got: %s, expect: %s", out, tc.expect)
+			}
+		})
+	}
+}
diff --git a/run.go b/run.go
index 70814c2..98aed47 100644
--- a/run.go
+++ b/run.go
@@ -51,7 +51,7 @@ func run(ctx context.Context, total, idx uint, junitDir string, argv []string, o
 		}
 	}
 
-	testLists, err := getTestListsFromPkgs(pkgs)
+	testLists, err := getTestListsFromPkgs(pkgs, detectTags(argv))
 	if err != nil {
 		return err
 	}