Index: firmware/App/Modes/ModePreTreat.c
===================================================================
diff -u -rc539499ea2dee6d62194d573ac93b313d9e2936d -r38f6b0b6ff1608eb1fd046e91add7fd2c65de4b1
--- firmware/App/Modes/ModePreTreat.c	(.../ModePreTreat.c)	(revision c539499ea2dee6d62194d573ac93b313d9e2936d)
+++ firmware/App/Modes/ModePreTreat.c	(.../ModePreTreat.c)	(revision 38f6b0b6ff1608eb1fd046e91add7fd2c65de4b1)
@@ -79,6 +79,13 @@
 *************************************************************************/
 U32 execPreTreatmentMode( void )
 {
+    BOOL stop = isStopButtonPressed();
+
+    if ( TRUE == stop )
+    {
+        activateAlarmNoData( ALARM_ID_TREATMENT_STOPPED_BY_USER );
+    }
+
     // execute mode state machine
     switch ( currentPreTreatmentState )
     {