diff --git a/admin/sync/exercice_files.go b/admin/sync/exercice_files.go
index 54a4ed53..0a0a9adc 100644
--- a/admin/sync/exercice_files.go
+++ b/admin/sync/exercice_files.go
@@ -127,6 +127,11 @@ func SyncExerciceFiles(i Importer, exercice fic.Exercice) (errs []string) {
 
 	// Import standard files
 	for _, fname := range files {
+		// Enforce file format
+		if path.Ext(fname) == "rar" || path.Ext(fname) == "7z" {
+			errs = append(errs, fmt.Sprintf("%q: WARNING %q use a forbidden archive type.", path.Base(exercice.Path), fname))
+		}
+
 		if f, err := i.importFile(path.Join(exercice.Path, "files", fname),
 			func(filePath string, origin string) (interface{}, error) {
 				return exercice.ImportFile(filePath, origin, digests[fname])
diff --git a/repochecker/update.go b/repochecker/update.go
index d99869b0..8144228c 100644
--- a/repochecker/update.go
+++ b/repochecker/update.go
@@ -1,3 +1,4 @@
+//go:build checkupdate
 // +build checkupdate
 
 package main
@@ -9,7 +10,7 @@ import (
 	"net/http"
 )
 
-const version = 10
+const version = 11
 
 func init() {
 	go checkUpdate()