diff --git a/ythdd_inv_tl.py b/ythdd_inv_tl.py
index ba3e810..d9b44e6 100644
--- a/ythdd_inv_tl.py
+++ b/ythdd_inv_tl.py
@@ -276,8 +276,12 @@ def rebuildFormatsFromYtdlpApi(ydata: dict):
 			newRow[   "qualityLabel"] = height + "p" + str(int(newRow['fps'])) * (newRow["fps"] > 30) # also a placeholder
 			newRow[           "size"] = width  + "x" + height
 
-		newRow["clen"]            = safeTraverse(params, ["clen"], default=safeTraverse(stream, ["filesize"], default="0"))
-		newRow["lmt"]             = safeTraverse(params,  ["lmt"], default="0")
+		newRow[           "clen"] = safeTraverse(params, ["clen"], default=safeTraverse(stream, ["filesize"], default="0"))
+		newRow[            "lmt"] = safeTraverse(params,  ["lmt"], default="0")
+
+		if newRow["clen"] is None:
+			# for clipious sake which expects a string
+			newRow["clen"] = "0"
 
 		newRow[ "projectionType"] = "RECTANGULAR" # clipious requires this to be mentioned explicitly and cannot be nulled
 		newRow[      "container"] = safeTraverse(stream, ["ext"], default="unknown_container")