diff --git a/lib/backup/azremote/azblob.go b/lib/backup/azremote/azblob.go
index 2e9b5bf07..b2f559829 100644
--- a/lib/backup/azremote/azblob.go
+++ b/lib/backup/azremote/azblob.go
@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"path"
 	"strings"
 	"time"
 
@@ -272,7 +273,7 @@ func (fs *FS) DeleteFile(filePath string) error {
 		return nil
 	}
 
-	path := fs.Dir + filePath
+	path := path.Join(fs.Dir, filePath)
 	return fs.delete(path)
 }
 
@@ -333,7 +334,7 @@ func (fs *FS) deleteObject(path string) error {
 //
 // The file is overwritten if it exists.
 func (fs *FS) CreateFile(filePath string, data []byte) error {
-	path := fs.Dir + filePath
+	path := path.Join(fs.Dir, filePath)
 	bc := fs.clientForPath(path)
 
 	ctx := context.Background()
@@ -350,8 +351,7 @@ func (fs *FS) CreateFile(filePath string, data []byte) error {
 
 // HasFile returns true if filePath exists at fs.
 func (fs *FS) HasFile(filePath string) (bool, error) {
-	path := fs.Dir + filePath
-
+	path := path.Join(fs.Dir, filePath)
 	bc := fs.clientForPath(path)
 
 	ctx := context.Background()
diff --git a/lib/backup/common/fs.go b/lib/backup/common/fs.go
index 42c051556..74fbf9080 100644
--- a/lib/backup/common/fs.go
+++ b/lib/backup/common/fs.go
@@ -45,15 +45,23 @@ type RemoteFS interface {
 	// UploadPart must upload part p from r to RemoteFS.
 	UploadPart(p Part, r io.Reader) error
 
-	// DeleteFile deletes filePath at RemoteFS
+	// DeleteFile deletes filePath at RemoteFS.
+	//
+	// filePath must use / as directory delimiters.
 	DeleteFile(filePath string) error
 
 	// CreateFile creates filePath at RemoteFS and puts data into it.
+	//
+	// filePath must use / as directory delimiters.
 	CreateFile(filePath string, data []byte) error
 
 	// HasFile returns true if filePath exists at RemoteFS.
+	//
+	// filePath must use / as directory delimiters.
 	HasFile(filePath string) (bool, error)
 
 	// ReadFile returns file contents at the given filePath.
+	//
+	// filePath must use / as directory delimiters.
 	ReadFile(filePath string) ([]byte, error)
 }
diff --git a/lib/backup/gcsremote/gcs.go b/lib/backup/gcsremote/gcs.go
index ce7ece62a..bca2c4fac 100644
--- a/lib/backup/gcsremote/gcs.go
+++ b/lib/backup/gcsremote/gcs.go
@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"path"
 	"strings"
 	"time"
 
@@ -211,7 +212,7 @@ func (fs *FS) object(p common.Part) *storage.ObjectHandle {
 //
 // The function does nothing if the filePath doesn't exists.
 func (fs *FS) DeleteFile(filePath string) error {
-	path := fs.Dir + filePath
+	path := path.Join(fs.Dir, filePath)
 	return fs.delete(path)
 }
 
@@ -265,7 +266,7 @@ func (fs *FS) deleteObject(path string) error {
 //
 // The file is overwritten if it exists.
 func (fs *FS) CreateFile(filePath string, data []byte) error {
-	path := fs.Dir + filePath
+	path := path.Join(fs.Dir, filePath)
 	o := fs.bkt.Object(path)
 	ctx := context.Background()
 	w := o.NewWriter(ctx)
@@ -286,7 +287,7 @@ func (fs *FS) CreateFile(filePath string, data []byte) error {
 
 // HasFile returns ture if filePath exists at fs.
 func (fs *FS) HasFile(filePath string) (bool, error) {
-	path := fs.Dir + filePath
+	path := path.Join(fs.Dir, filePath)
 	o := fs.bkt.Object(path)
 	ctx := context.Background()
 	_, err := o.Attrs(ctx)
@@ -301,7 +302,8 @@ func (fs *FS) HasFile(filePath string) (bool, error) {
 
 // ReadFile returns the content of filePath at fs.
 func (fs *FS) ReadFile(filePath string) ([]byte, error) {
-	o := fs.bkt.Object(fs.Dir + filePath)
+	path := path.Join(fs.Dir, filePath)
+	o := fs.bkt.Object(path)
 	ctx := context.Background()
 	r, err := o.NewReader(ctx)
 	if err != nil {
diff --git a/lib/backup/s3remote/s3.go b/lib/backup/s3remote/s3.go
index 45bc8cfc1..fc37e86ed 100644
--- a/lib/backup/s3remote/s3.go
+++ b/lib/backup/s3remote/s3.go
@@ -5,6 +5,7 @@ import (
 	"context"
 	"fmt"
 	"io"
+	"path"
 	"strings"
 
 	"github.com/aws/aws-sdk-go-v2/aws"
@@ -53,7 +54,7 @@ type FS struct {
 	// Path to S3 configs file.
 	ConfigFilePath string
 
-	// GCS bucket to use.
+	// S3 bucket to use.
 	Bucket string
 
 	// Directory in the bucket to write to.
@@ -292,7 +293,7 @@ func (fs *FS) DeleteFile(filePath string) error {
 		return nil
 	}
 
-	path := fs.Dir + filePath
+	path := path.Join(fs.Dir, filePath)
 	return fs.delete(path)
 }
 
@@ -344,7 +345,7 @@ func (fs *FS) deleteObjectWithVersions(path string) error {
 //
 // The file is overwritten if it already exists.
 func (fs *FS) CreateFile(filePath string, data []byte) error {
-	path := fs.Dir + filePath
+	path := path.Join(fs.Dir, filePath)
 	sr := &statReader{
 		r: bytes.NewReader(data),
 	}
@@ -367,7 +368,7 @@ func (fs *FS) CreateFile(filePath string, data []byte) error {
 
 // HasFile returns true if filePath exists at fs.
 func (fs *FS) HasFile(filePath string) (bool, error) {
-	path := fs.Dir + filePath
+	path := path.Join(fs.Dir, filePath)
 	input := &s3.GetObjectInput{
 		Bucket: aws.String(fs.Bucket),
 		Key:    aws.String(path),
@@ -387,7 +388,7 @@ func (fs *FS) HasFile(filePath string) (bool, error) {
 
 // ReadFile returns the content of filePath at fs.
 func (fs *FS) ReadFile(filePath string) ([]byte, error) {
-	p := fs.Dir + filePath
+	p := path.Join(fs.Dir, filePath)
 	input := &s3.GetObjectInput{
 		Bucket: aws.String(fs.Bucket),
 		Key:    aws.String(p),