diff --git a/backend/Dockerfile b/backend/Dockerfile
index fe6e757e4..43ea47d22 100644
--- a/backend/Dockerfile
+++ b/backend/Dockerfile
@@ -42,7 +42,7 @@ ENV TZ=UTC \
     AWS_REGION_ASSETS=eu-central-1 \
     CACHE_ASSETS=false \
     ASSETS_SIZE_LIMIT=6291456 \
-    FS_CLEAN_HRS=0
+    FS_CLEAN_HRS=240
 
 
 ARG SERVICE_NAME
diff --git a/backend/pkg/env/vars.go b/backend/pkg/env/vars.go
index 64e586cc3..a5334b301 100644
--- a/backend/pkg/env/vars.go
+++ b/backend/pkg/env/vars.go
@@ -18,24 +18,24 @@ func StringOptional(key string) string {
 	return os.Getenv(key)
 }
 
-func Uint16(key string) uint16 {
-	v := String(key)
-	n, _ := strconv.ParseUint(v, 10, 16)
-	if n == 0 {
-		log.Fatalln(key + " has a wrong value")
-	}
-	return uint16(n)
-}
-
 func Uint64(key string) uint64 {
 	v := String(key)
-	n, _ := strconv.ParseUint(v, 10, 64)
-	if n == 0 {
-		log.Fatalln(key + " has a wrong value")
+	n, err := strconv.ParseUint(v, 10, 64)
+	if err != nil {
+		log.Fatalln(key + " has a wrong value. ", err)
 	}
 	return n
 }
 
+func Uint16(key string) uint16 {
+	v := String(key)
+	n, err := strconv.ParseUint(v, 10, 16)
+	if err != nil {
+		log.Fatalln(key + " has a wrong value. ", err)
+	}
+	return uint16(n)
+}
+
 func Int(key string) int {
 	return int(Uint64(key))
 }