diff --git a/admin/main.go b/admin/main.go
index 907c04c7..545cf827 100644
--- a/admin/main.go
+++ b/admin/main.go
@@ -128,6 +128,9 @@ func main() {
 		sync.GlobalImporter, _ = sync.NewCloudImporter(cloudDAVBase, cloudUsername, cloudPassword)
 	}
 	if sync.GlobalImporter != nil {
+		if err := sync.GlobalImporter.Init(); err != nil {
+			log.Fatal("Unable to initialize the importer:", err)
+		}
 		log.Println("Using", sync.GlobalImporter.Kind())
 	}
 
diff --git a/admin/sync/exercices.go b/admin/sync/exercices.go
index afe43038..bf42978f 100644
--- a/admin/sync/exercices.go
+++ b/admin/sync/exercices.go
@@ -243,6 +243,12 @@ func SyncExercice(i Importer, theme fic.Theme, epath string, dmap *map[int64]fic
 
 // SyncExercices imports new or updates existing exercices, in a given theme.
 func SyncExercices(i Importer, theme fic.Theme) (errs []string) {
+	if !avoidImporterSync() {
+		if err := i.Sync(); err != nil {
+			errs = append(errs, err.Error())
+		}
+	}
+
 	if exercices, err := GetExercices(i, theme); err != nil {
 		errs = append(errs, err.Error())
 	} else {
diff --git a/admin/sync/file.go b/admin/sync/file.go
index bc3749fe..b6d5d970 100644
--- a/admin/sync/file.go
+++ b/admin/sync/file.go
@@ -19,6 +19,10 @@ import (
 type Importer interface {
 	// Kind returns information about the Importer, for human interrest.
 	Kind() string
+	// init performs the importer initialization.
+	Init() error
+	// sync tries to pull the latest modification of the underlying storage.
+	Sync() error
 	// exists checks if the given location exists from the Importer point of view.
 	exists(filename string) bool
 	// toURL gets the full path/URL to the given file, the Importer will look internaly (used for debuging purpose).
diff --git a/admin/sync/full.go b/admin/sync/full.go
index f45d5f92..64aeccb0 100644
--- a/admin/sync/full.go
+++ b/admin/sync/full.go
@@ -22,6 +22,11 @@ var oneThemeDeepSync sync.Mutex
 // DeepSyncProgress expose the progression of the depp synchronization (0 = 0%, 255 = 100%).
 var DeepSyncProgress uint8
 
+// avoidImporterSync checks if Sync should be called or not.
+func avoidImporterSync() bool {
+	return DeepSyncProgress > 1 && DeepSyncProgress < 255
+}
+
 // SpeedySyncDeep performs a recursive synchronisation without importing files.
 func SpeedySyncDeep(i Importer) (errs map[string][]string) {
 	oneDeepSync.Lock()
@@ -36,6 +41,11 @@ func SpeedySyncDeep(i Importer) (errs map[string][]string) {
 	errs = map[string][]string{}
 
 	startTime := time.Now()
+
+	if err := i.Sync(); err != nil {
+		errs["_sync"] = []string{err.Error()}
+	}
+
 	errs["_date"] = []string{fmt.Sprintf("%v", startTime)}
 	errs["_themes"] = SyncThemes(i)
 
@@ -89,6 +99,11 @@ func SyncDeep(i Importer) (errs map[string][]string) {
 	errs = map[string][]string{}
 
 	startTime := time.Now()
+
+	if err := i.Sync(); err != nil {
+		errs["_sync"] = []string{err.Error()}
+	}
+
 	errs["_date"] = []string{fmt.Sprintf("%v", startTime)}
 	errs["_themes"] = SyncThemes(i)
 
@@ -171,6 +186,10 @@ func SyncThemeDeep(i Importer, theme fic.Theme, tid int, themeStep uint8) (errs
 	oneThemeDeepSync.Lock()
 	defer oneThemeDeepSync.Unlock()
 
+	if err := i.Sync(); err != nil {
+		errs = append(errs, err.Error())
+	}
+
 	DeepSyncProgress = 3 + uint8(tid)*themeStep
 	errs = SyncExercices(i, theme)
 
diff --git a/admin/sync/importer_cloud.go b/admin/sync/importer_cloud.go
index 70811e6d..5cbf1731 100644
--- a/admin/sync/importer_cloud.go
+++ b/admin/sync/importer_cloud.go
@@ -38,6 +38,14 @@ func (i CloudImporter) Kind() string {
 	return "cloud file importer: " + i.baseDAV.String()
 }
 
+func (i CloudImporter) Init() error {
+	return nil
+}
+
+func (i CloudImporter) Sync() error {
+	return nil
+}
+
 func (i CloudImporter) exists(filename string) bool {
 	fullURL := i.baseDAV
 	fullURL.Path = path.Join(fullURL.Path, filename)
diff --git a/admin/sync/importer_localfs.go b/admin/sync/importer_localfs.go
index 515be07a..e088cbb6 100644
--- a/admin/sync/importer_localfs.go
+++ b/admin/sync/importer_localfs.go
@@ -2,6 +2,7 @@ package sync
 
 import (
 	"bufio"
+	"fmt"
 	"io/ioutil"
 	"os"
 	"path"
@@ -11,7 +12,7 @@ import (
 // inside a local directory from your filesystem.
 type LocalImporter struct {
 	// Base is the root directory used by the LocalImporter. It should contains all themes.
-	Base    string
+	Base string
 	// Symlink changes the normal file copy/concatenate behaviour to symlink/concatenate.
 	// If enable, your base directory must be accessible by the frontend processus as it will follow the symlink.
 	Symlink bool
@@ -25,6 +26,23 @@ func (i LocalImporter) Kind() string {
 	}
 }
 
+func (i LocalImporter) Init() error {
+	if f, err := os.Stat(i.Base); os.IsNotExist(err) {
+		if err = os.Mkdir(i.Base, 0751); err != nil {
+			return err
+		}
+	} else if err != nil {
+		return err
+	} else if !f.IsDir() {
+		return fmt.Errorf("%q exists and is not a directory", i.Base)
+	}
+	return nil
+}
+
+func (i LocalImporter) Sync() error {
+	return nil
+}
+
 func (i LocalImporter) exists(filename string) bool {
 	_, err := os.Stat(i.toURL(filename))
 	return !os.IsNotExist(err)
@@ -46,7 +64,7 @@ func (i LocalImporter) importFile(URI string, next func(string, string) (interfa
 			os.Symlink(i.toURL(URI), dest)
 			return next(dest, URI)
 		} else {
-			os.Symlink(i.toURL(URI) + "_MERGED", dest)
+			os.Symlink(i.toURL(URI)+"_MERGED", dest)
 			return ImportFile(i, URI, next)
 		}
 	} else {
diff --git a/admin/sync/themes.go b/admin/sync/themes.go
index 677c5229..4a44da4e 100644
--- a/admin/sync/themes.go
+++ b/admin/sync/themes.go
@@ -173,9 +173,7 @@ func BuildTheme(i Importer, tdir string) (th *fic.Theme, errs []string) {
 }
 
 // SyncThemes imports new or updates existing themes.
-func SyncThemes(i Importer) []string {
-	var errs []string
-
+func SyncThemes(i Importer) (errs []string) {
 	if themes, err := GetThemes(i); err != nil {
 		errs = append(errs, err.Error())
 	} else {
@@ -233,7 +231,7 @@ func SyncThemes(i Importer) []string {
 		}
 	}
 
-	return errs
+	return
 }
 
 // ApiListRemoteThemes is an accessor letting foreign packages to access remote themes list.