diff --git a/central/central.go b/central/central.go
index f3f3e249..20bfed9c 100644
--- a/central/central.go
+++ b/central/central.go
@@ -15,11 +15,11 @@ import (
 	"text/template"
 	"time"
 
+	"github.com/k1LoW/octocov/badge"
 	"github.com/k1LoW/octocov/datastore"
 	"github.com/k1LoW/octocov/datastore/local"
 	"github.com/k1LoW/octocov/gh"
 	"github.com/k1LoW/octocov/internal"
-	"github.com/k1LoW/octocov/badge"
 	"github.com/k1LoW/octocov/report"
 )
 
@@ -266,8 +266,8 @@ func (c *Central) renderIndex(wr io.Writer) error {
 	d := map[string]any{
 		"Host":          host,
 		"Reports":       c.reports,
-		"BadgesLinkRel": badgesLinkRel,
-		"BadgesURLRel":  badgesURLRel,
+		"BadgesLinkRel": filepath.ToSlash(badgesLinkRel),
+		"BadgesURLRel":  filepath.ToSlash(badgesURLRel),
 		"RootURL":       rootURL,
 		"IsPrivate":     isPrivate,
 		"Query":         query,
diff --git a/config/build.go b/config/build.go
index fa864990..dba48177 100644
--- a/config/build.go
+++ b/config/build.go
@@ -4,7 +4,6 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
-	"strings"
 
 	"github.com/k1LoW/octocov/internal"
 )
@@ -45,7 +44,7 @@ func (c *Config) Build() {
 		if c.Central.Root == "" {
 			c.Central.Root = "."
 		}
-		if !strings.HasPrefix(c.Central.Root, "/") {
+		if !filepath.IsAbs(c.Central.Root) {
 			c.Central.Root = filepath.Clean(filepath.Join(c.Root(), c.Central.Root))
 		}
 		if len(c.Central.Reports.Datastores) == 0 {
diff --git a/config/config.go b/config/config.go
index 94b41233..8cf57926 100644
--- a/config/config.go
+++ b/config/config.go
@@ -165,7 +165,7 @@ func (c *Config) Load(path string) error {
 	if path == "" {
 		return nil
 	}
-	if strings.HasPrefix(path, "/") {
+	if filepath.IsAbs(path) {
 		c.path = path
 	} else {
 		c.path = filepath.Join(c.wd, path)
diff --git a/coverage/coverage.go b/coverage/coverage.go
index dd65cab5..6c555657 100644
--- a/coverage/coverage.go
+++ b/coverage/coverage.go
@@ -94,7 +94,7 @@ func (fc FileCoverages) FuzzyFindByFile(file string) (*FileCoverage, error) { //
 			continue
 		}
 		// When coverages are recorded in the package path. ( ex. org/repo/package/path/to/Target.kt
-		if !strings.HasPrefix(c.File, "/") && strings.HasSuffix(file, c.File) {
+		if !filepath.IsAbs(c.File) && strings.HasSuffix(file, c.File) {
 			if match == nil || len(match.File) > len(c.File) {
 				match = c
 			}
@@ -130,7 +130,7 @@ func (fc FileCoverages) PathPrefix() (string, error) { //nostyle:recvtype
 		p = p[:i]
 	}
 	s := strings.Join(p, "/")
-	if s == "" && strings.HasPrefix(fc[0].File, "/") {
+	if s == "" && filepath.IsAbs(fc[0].File) {
 		s = "/"
 	}
 	if s == "." {
@@ -174,7 +174,7 @@ func (dc DiffFileCoverages) FuzzyFindByFile(file string) (*DiffFileCoverage, err
 			continue
 		}
 		// When coverages are recorded in the package path. ( ex. org/repo/package/path/to/Target.kt
-		if !strings.HasPrefix(c.File, "/") && strings.HasSuffix(file, c.File) {
+		if !filepath.IsAbs(c.File) && strings.HasSuffix(file, c.File) {
 			if match == nil || len(match.File) > len(c.File) {
 				match = c
 			}
diff --git a/datastore/datastore.go b/datastore/datastore.go
index d7e4012a..944f3bd9 100644
--- a/datastore/datastore.go
+++ b/datastore/datastore.go
@@ -222,7 +222,7 @@ func parse(u, root string) (Type, []string, error) {
 		return Mackerel, []string{service}, nil
 	default:
 		p := strings.TrimSuffix(strings.TrimPrefix(strings.TrimPrefix(u, "file://"), "local://"), "/")
-		if strings.HasPrefix(p, "/") {
+		if filepath.IsAbs(p) {
 			root = p
 		} else {
 			root = filepath.Join(root, p)