diff --git a/libgnucash/engine/iso-4217-currencies.xml b/libgnucash/engine/iso-4217-currencies.xml
index 8812ff53e2..a17e75fe84 100644
--- a/libgnucash/engine/iso-4217-currencies.xml
+++ b/libgnucash/engine/iso-4217-currencies.xml
@@ -1743,7 +1743,7 @@
   namespace="ISO4217"
   exchange-code="478"
   parts-per-unit="5"
-  smallest-fraction="5"
+  smallest-fraction="100"
   local-symbol="UM"
 />
 <!-- "MRU" - "Ouguiya"