diff --git a/admin/sync/full.go b/admin/sync/full.go
index a835bded..acb7df62 100644
--- a/admin/sync/full.go
+++ b/admin/sync/full.go
@@ -24,12 +24,18 @@ var DeepSyncProgress uint8
 // SyncDeep performs a recursive synchronisation: from themes to challenge items.
 func SyncDeep(i Importer) (errs map[string][]string) {
 	oneDeepSync.Lock()
-	defer oneDeepSync.Unlock()
+	defer func(){
+		oneDeepSync.Unlock()
+		if DeepSyncProgress != 255 {
+			log.Printf("Full synchronization terminated at step %d/255", DeepSyncProgress)
+		}
+	}()
 	DeepSyncProgress = 1
 
 	errs = map[string][]string{}
 
-	errs["_date"] = []string{fmt.Sprintf("%v", time.Now())}
+	startTime := time.Now()
+	errs["_date"] = []string{fmt.Sprintf("%v", startTime)}
 	errs["_themes"] = SyncThemes(i)
 
 	if themes, err := fic.GetThemes(); err == nil {
@@ -43,6 +49,8 @@ func SyncDeep(i Importer) (errs map[string][]string) {
 			if exercices, err := theme.GetExercices(); err == nil {
 				var exerciceStep uint8 = themeStep / uint8(len(exercices))
 				for eid, exercice := range exercices {
+					log.Printf("Full synchronization in progress: %d/255 - doing Theme %q, Exercice %q: %q\n", DeepSyncProgress, theme.Name, exercice.Title, exercice.Path)
+
 					DeepSyncProgress = 3 + uint8(tid) * themeStep + uint8(eid) * exerciceStep
 					errs[theme.Name] = append(errs[theme.Name], SyncExerciceFiles(i, exercice)...)
 
@@ -82,5 +90,6 @@ func SyncDeep(i Importer) (errs map[string][]string) {
 	}
 
 	DeepSyncProgress = 255
+	log.Println("Full synchronization done in", time.Since(startTime))
 	return
 }