diff --git a/doc/version-history.rst b/doc/version-history.rst
index 2895492f0..63a41661b 100644
--- a/doc/version-history.rst
+++ b/doc/version-history.rst
@@ -31,6 +31,10 @@ v21.0.0
 
 * Interface updates:
 
+  * ATMCS
+
+    * Fix typo in the ``ATMCS_nasmyth_m3_mountMotorEncoders`` telemetry topic name.
+
   * MTRotator
 
     * Add FaultSubstate enumeration (updated).
diff --git a/python/lsst/ts/xml/data/sal_interfaces/ATMCS/ATMCS_Telemetry.xml b/python/lsst/ts/xml/data/sal_interfaces/ATMCS/ATMCS_Telemetry.xml
index 557447500..5bb09a00c 100644
--- a/python/lsst/ts/xml/data/sal_interfaces/ATMCS/ATMCS_Telemetry.xml
+++ b/python/lsst/ts/xml/data/sal_interfaces/ATMCS/ATMCS_Telemetry.xml
@@ -376,7 +376,7 @@
   </SALTelemetry>
   <SALTelemetry>
     <Subsystem>ATMCS</Subsystem>
-    <EFDB_Topic>ATMCS_nasymth_m3_mountMotorEncoders</EFDB_Topic>
+    <EFDB_Topic>ATMCS_nasmyth_m3_mountMotorEncoders</EFDB_Topic>
     <Description>Position reported by Nasmyth and M3 mount encoders</Description>
     <item>
       <EFDB_Name>cRIO_timestamp</EFDB_Name>