diff --git a/classify.go b/classify.go
index fdcde4f..5087887 100644
--- a/classify.go
+++ b/classify.go
@@ -2,6 +2,7 @@ package sisyphus
 
 import (
 	"os"
+	"path/filepath"
 
 	log "github.com/sirupsen/logrus"
 
@@ -173,7 +174,7 @@ func (m *Mail) Classify(db *bolt.DB, dir Maildir) (err error) {
 
 	// Move mail around if junk.
 	if junk {
-		err = os.Rename(string(dir)+"/new/"+m.Key, string(dir)+"/.Junk/cur/"+m.Key)
+		err = os.Rename(filepath.Join(string(dir), "new", m.Key), filepath.Join(string(dir), ".Junk", "cur", m.Key))
 		if err != nil {
 			return err
 		}
diff --git a/database.go b/database.go
index cf30997..d214a6b 100644
--- a/database.go
+++ b/database.go
@@ -1,6 +1,8 @@
 package sisyphus
 
 import (
+	"path/filepath"
+
 	log "github.com/sirupsen/logrus"
 
 	"github.com/boltdb/bolt"
@@ -14,7 +16,7 @@ func openDB(m Maildir) (db *bolt.DB, err error) {
 	}).Info("Loading database")
 	// Open the sisyphus.db data file in your current directory.
 	// It will be created if it doesn't exist.
-	db, err = bolt.Open(string(m)+"/sisyphus.db", 0600, nil)
+	db, err = bolt.Open(filepath.Join(string(m), "sisyphus.db"), 0600, nil)
 	if err != nil {
 		return db, err
 	}
@@ -76,7 +78,7 @@ func LoadDatabases(d []Maildir) (databases map[Maildir]*bolt.DB, err error) {
 func LoadBackupDatabases(d []Maildir) (databases map[Maildir]*bolt.DB, err error) {
 	databases = make(map[Maildir]*bolt.DB)
 	for _, val := range d {
-		databases[val], err = bolt.Open(string(val)+"/sisyphus.db.backup", 0600, nil)
+		databases[val], err = bolt.Open(filepath.Join(string(val), "sisyphus.db.backup"), 0600, nil)
 		if err != nil {
 			return databases, err
 		}
@@ -93,7 +95,7 @@ func CloseDatabases(databases map[Maildir]*bolt.DB) {
 		err := val.Close()
 		if err != nil {
 			log.WithFields(log.Fields{
-				"db": string(key) + "/sisyphus.db",
+				"db": filepath.Join(string(key), "sisyphus.db"),
 			}).Error("Unable to close database")
 		}
 		log.WithFields(log.Fields{
diff --git a/mail.go b/mail.go
index 4b18a9c..4867c81 100644
--- a/mail.go
+++ b/mail.go
@@ -8,6 +8,7 @@ import (
 	"mime/quotedprintable"
 	"net/mail"
 	"os"
+	"path/filepath"
 	"regexp"
 	"strings"
 	"unicode/utf8"
@@ -37,15 +38,15 @@ func (d Maildir) CreateDirs() error {
 		"dir": dir,
 	}).Info("Create missing directories")
 
-	err := os.MkdirAll(dir+"/.Junk/cur", 0700)
+	err := os.MkdirAll(filepath.Join(dir, ".Junk", "cur"), 0700)
 	if err != nil {
 		return err
 	}
-	err = os.MkdirAll(dir+"/new", 0700)
+	err = os.MkdirAll(filepath.Join(dir, "new"), 0700)
 	if err != nil {
 		return err
 	}
-	err = os.MkdirAll(dir+"/cur", 0700)
+	err = os.MkdirAll(filepath.Join(dir, "cur"), 0700)
 
 	return err
 }
@@ -59,7 +60,7 @@ func (d Maildir) Index() (m []*Mail, err error) {
 		"dir": dir,
 	}).Info("Start indexing mails")
 
-	dirs := []string{dir, dir + "/.Junk"}
+	dirs := []string{dir, filepath.Join(dir, ".Junk")}
 	for _, val := range dirs {
 		j, err := maildir.Dir(val).Keys()
 		if err != nil {
@@ -68,7 +69,7 @@ func (d Maildir) Index() (m []*Mail, err error) {
 		for _, v := range j {
 			var new Mail
 			new.Key = v
-			if val == dir+"/.Junk" {
+			if val == filepath.Join(dir, ".Junk") {
 				new.Junk = true
 			}
 			m = append(m, &new)
@@ -89,9 +90,9 @@ func (m *Mail) Load(dir Maildir) (err error) {
 
 	switch {
 	case m.Junk:
-		dir = dir + Maildir("/.Junk")
+		dir = Maildir(filepath.Join(string(dir), ".Junk"))
 	case m.New:
-		dir = dir + Maildir("/new")
+		dir = Maildir(filepath.Join(string(dir), "new"))
 	}
 
 	message, err = maildir.Dir(dir).Message(m.Key)
diff --git a/sisyphus/sisyphus.go b/sisyphus/sisyphus.go
index 183509e..49e3f90 100644
--- a/sisyphus/sisyphus.go
+++ b/sisyphus/sisyphus.go
@@ -4,6 +4,7 @@ import (
 	"bufio"
 	"fmt"
 	"os"
+	"path/filepath"
 	"strings"
 	"time"
 
@@ -202,11 +203,11 @@ COPYRIGHT:
 				}()
 
 				for _, val := range maildirs {
-					err = watcher.Add(string(val) + "/new")
+					err = watcher.Add(filepath.Join(string(val), "new"))
 					if err != nil {
 						log.WithFields(log.Fields{
 							"err": err,
-							"dir": val + "/new",
+							"dir": filepath.Join(string(val), "new"),
 						}).Error("Cannot watch directory")
 					}
 				}
@@ -282,7 +283,7 @@ func backup(maildirs []sisyphus.Maildir, dbs map[sisyphus.Maildir]*bolt.DB) {
 	for _, d := range maildirs {
 		db := dbs[d]
 
-		backup, err := os.Create(string(d) + "/sisyphus.db.backup")
+		backup, err := os.Create(filepath.Join(string(d), "sisyphus.db.backup"))
 		if err != nil {
 			log.WithFields(log.Fields{
 				"err": err,