diff --git a/src/yunohost/backup.py b/src/yunohost/backup.py
index f10b112ac..8c7d53b1c 100644
--- a/src/yunohost/backup.py
+++ b/src/yunohost/backup.py
@@ -2272,13 +2272,16 @@ def backup_info(name, with_details=False, human_readable=False):
         if "hooks" in info.keys():
             system_key = "hooks"
 
-        
         if "size_details" in info.keys():
             for name, key_info in info["apps"].items():
                 if name in info["size_details"]["apps"].keys():
                     key_info["size"] = info["size_details"]["apps"][name]
+                    if human_readable:
+                        key_info["size"] = binary_to_human(key_info["size"]) + 'B'
                 else:
                     key_info["size"] = 0
+                    if human_readable:
+                        key_info["size"] = "?"
 
         result["apps"] = info["apps"]
         result["system"] = info[system_key]