diff --git a/changelogs/client_server/newsfragments/1169.clarification b/changelogs/client_server/newsfragments/1169.clarification
new file mode 100644
index 00000000..6d550dbc
--- /dev/null
+++ b/changelogs/client_server/newsfragments/1169.clarification
@@ -0,0 +1 @@
+Clarify the power levels integer range.
\ No newline at end of file
diff --git a/data/event-schemas/schema/m.room.power_levels.yaml b/data/event-schemas/schema/m.room.power_levels.yaml
index ae38f88c..f9d5d124 100644
--- a/data/event-schemas/schema/m.room.power_levels.yaml
+++ b/data/event-schemas/schema/m.room.power_levels.yaml
@@ -42,6 +42,9 @@ description: |-
   `m.room.power_levels` event as soon as it is created. See also the
   documentation of the `/createRoom` API.
 
+  Note: the allowed range for power level values is `[-(2**53)+1, (2**53)-1]`,
+  as required by the [Canonical JSON specification](/appendices/#canonical-json).
+
 properties:
   content:
     properties: