diff --git a/include/common/htx.h b/include/common/htx.h
index 9cbc95300..cd7db0526 100644
--- a/include/common/htx.h
+++ b/include/common/htx.h
@@ -280,7 +280,7 @@ static inline struct htx_sl *htx_get_stline(struct htx *htx)
 {
 	struct htx_sl *sl = NULL;
 
-	if (htx->sl_off != -1)
+	if (htx->used && htx->sl_off != -1)
 		sl = ((void *)htx->blocks + htx->sl_off);
 
 	return sl;