diff --git a/internal/store/.gitignore b/internal/store/.gitignore
deleted file mode 100644
index 32bcdf1ac..000000000
--- a/internal/store/.gitignore
+++ /dev/null
@@ -1 +0,0 @@
-/test
\ No newline at end of file
diff --git a/internal/store/store.go b/internal/store/store.go
index 2e04b884a..4f0f08e9e 100644
--- a/internal/store/store.go
+++ b/internal/store/store.go
@@ -11,6 +11,8 @@ import (
 
 type (
 	store struct {
+		fs afero.Fs
+
 		namespace string
 
 		originalFn func(id uint64, ext string) string
@@ -29,15 +31,27 @@ type (
 	}
 )
 
-func New(namespace string) (Store, error) {
+var (
+	defPreviewFn = func(id uint64, ext string) string {
+		return fmt.Sprintf("%d_preview.%s", id, ext)
+	}
+
+	defOriginalFn = func(id uint64, ext string) string {
+		return fmt.Sprintf("%d.%s", id, ext)
+	}
+)
+
+func New(namespace string) (*store, error) {
+	return NewWithAfero(afero.NewOsFs(), namespace)
+}
+
+func NewWithAfero(fs afero.Fs, namespace string) (*store, error) {
 	return &store{
+		fs:        fs,
 		namespace: namespace,
-		originalFn: func(id uint64, ext string) string {
-			return fmt.Sprintf("%d.%s", id, ext)
-		},
-		previewFn: func(id uint64, ext string) string {
-			return fmt.Sprintf("%d_preview.%s", id, ext)
-		},
+
+		originalFn: defOriginalFn,
+		previewFn:  defPreviewFn,
 	}, nil
 }
 
@@ -65,18 +79,19 @@ func (s *store) Preview(id uint64, ext string) string {
 	return path.Join(s.namespace, s.previewFn(id, ext))
 }
 
-func (s *store) Save(filename string, contents io.Reader) error {
+func (s *store) Save(filename string, contents io.Reader) (err error) {
 	// check filename for validity
-	if err := s.check(filename); err != nil {
-		return err
+	if err = s.check(filename); err != nil {
+		return
 	}
 
 	folder := path.Dir(filename)
 
-	fs := afero.NewOsFs()
-	fs.MkdirAll(folder, 0755)
+	if err = s.fs.MkdirAll(folder, 0755); err != nil {
+		return
+	}
 
-	return afero.WriteReader(fs, filename, contents)
+	return afero.WriteReader(s.fs, filename, contents)
 }
 
 func (s *store) Remove(filename string) error {
@@ -85,8 +100,7 @@ func (s *store) Remove(filename string) error {
 		return err
 	}
 
-	fs := afero.NewOsFs()
-	return fs.Remove(filename)
+	return s.fs.Remove(filename)
 }
 
 func (s *store) Open(filename string) (afero.File, error) {
@@ -95,6 +109,5 @@ func (s *store) Open(filename string) (afero.File, error) {
 		return nil, err
 	}
 
-	fs := afero.NewOsFs()
-	return fs.Open(filename)
+	return s.fs.Open(filename)
 }
diff --git a/internal/store/store_test.go b/internal/store/store_test.go
index 9732bb532..8e4799a9c 100644
--- a/internal/store/store_test.go
+++ b/internal/store/store_test.go
@@ -5,6 +5,8 @@ import (
 	"io"
 	"testing"
 
+	"github.com/spf13/afero"
+
 	"github.com/cortezaproject/corteza-server/internal/test"
 )
 
@@ -15,7 +17,8 @@ func TestStore(t *testing.T) {
 		return b.String()
 	}
 
-	store, err := New("test")
+	store, err := NewWithAfero(afero.NewMemMapFs(), "test")
+
 	test.Assert(t, err == nil, "Unexpected error when creating store: %+v", err)
 	test.Assert(t, store != nil, "Expected non-nil return for new store")
 	test.Assert(t, store.Namespace() == "test", "Unexpected store namespace: test != %s", store.Namespace())
diff --git a/messaging/service/service.go b/messaging/service/service.go
index a8793b1ac..0d3d5a235 100644
--- a/messaging/service/service.go
+++ b/messaging/service/service.go
@@ -29,6 +29,7 @@ type (
 )
 
 var (
+	DefaultStore       store.Store
 	DefaultPermissions permissionServicer
 
 	DefaultLogger *zap.Logger
@@ -46,10 +47,12 @@ var (
 func Init(ctx context.Context, log *zap.Logger, c Config) (err error) {
 	DefaultLogger = log.Named("service")
 
-	fs, err := store.New(c.Storage.Path)
-	log.Info("initializing store", zap.String("path", c.Storage.Path), zap.Error(err))
-	if err != nil {
-		return err
+	if DefaultStore == nil {
+		DefaultStore, err = store.New(c.Storage.Path)
+		log.Info("initializing store", zap.String("path", c.Storage.Path), zap.Error(err))
+		if err != nil {
+			return err
+		}
 	}
 
 	client, err := http.New(&http.Config{
@@ -59,15 +62,17 @@ func Init(ctx context.Context, log *zap.Logger, c Config) (err error) {
 		return err
 	}
 
-	DefaultPermissions = permissions.Service(
-		ctx,
-		DefaultLogger,
-		permissions.Repository(repository.DB(ctx), "messaging_permission_rules"))
+	if DefaultPermissions == nil {
+		// Do not override permissions service stored under DefaultPermissions
+		// to allow integration tests to inject own permission service
+		pRepo := permissions.Repository(repository.DB(ctx), "messaging_permission_rules")
+		DefaultPermissions = permissions.Service(ctx, DefaultLogger, pRepo)
+	}
 	DefaultAccessControl = AccessControl(DefaultPermissions)
 
 	DefaultEvent = Event(ctx)
 	DefaultChannel = Channel(ctx)
-	DefaultAttachment = Attachment(ctx, fs)
+	DefaultAttachment = Attachment(ctx, DefaultStore)
 	DefaultMessage = Message(ctx)
 	DefaultCommand = Command(ctx)
 	DefaultWebhook = Webhook(ctx, client)