diff --git a/libgnucash/engine/iso-4217-currencies.xml b/libgnucash/engine/iso-4217-currencies.xml
index 2737cb227e..9624d807a0 100644
--- a/libgnucash/engine/iso-4217-currencies.xml
+++ b/libgnucash/engine/iso-4217-currencies.xml
@@ -1748,6 +1748,7 @@
   local-symbol="UM"
 />
 <!-- "MRU" - "Ouguiya"
+;; Bug 797319: In cash parts-per-unit is still 5, but not in banking 
 -->
 <currency
   isocode="MRU"