diff --git a/lib/Slic3r/GCode.pm b/lib/Slic3r/GCode.pm
index a135be271..7653e4c32 100644
--- a/lib/Slic3r/GCode.pm
+++ b/lib/Slic3r/GCode.pm
@@ -421,7 +421,7 @@ sub set_temperature {
         : ('M104', 'set temperature');
     my $gcode = sprintf "$code %s%d %s; $comment\n",
         ($Slic3r::Config->gcode_flavor eq 'mach3' ? 'P' : 'S'), $temperature,
-        (defined $tool && $tool != $self->extruder->id) ? "T$tool " : "";
+        (defined $tool && $self->multiple_extruders) ? "T$tool " : "";
     
     $gcode .= "M116 ; wait for temperature to be reached\n"
         if $Slic3r::Config->gcode_flavor eq 'teacup' && $wait;