diff --git a/src/corelib/text/qlocale.qdoc b/src/corelib/text/qlocale.qdoc
index 39534385f82..dad18e1e10c 100644
--- a/src/corelib/text/qlocale.qdoc
+++ b/src/corelib/text/qlocale.qdoc
@@ -1037,7 +1037,8 @@
     This enum defines which units are used for measurement.
 
     \value MetricSystem This value indicates metric units, such as meters,
-            centimeters and millimeters.
+            centimeters and millimeters, based on \l
+            {https://www.bipm.org/en/measurement-units} {SI}.
     \value ImperialUSSystem This value indicates imperial units, such as inches and
             miles as they are used in the United States.
     \value ImperialUKSystem This value indicates imperial units, such as inches and