diff --git a/src/mode/fdm/export.js b/src/mode/fdm/export.js
index 51f936f4..11d5b7a6 100644
--- a/src/mode/fdm/export.js
+++ b/src/mode/fdm/export.js
@@ -21,6 +21,7 @@
             getRangeParameters = FDM.getRangeParameters,
             device = settings.device,
             extruders = device.extruders,
+            extused = Object.keys(print.extruders).map(v => parseInt(v)),
             gcodeFan = device.gcodeFan,
             gcodeLayer = device.gcodeLayer,
             gcodeTrack = device.gcodeTrack,
@@ -265,8 +266,8 @@
                     }
                 });
             }
-            if (line.indexOf("{tool}") > 0 && extruders.length > 1) {
-                for (let i=0; i<extruders.length; i++) {
+            if (line.indexOf("{tool}") > 0 && extused.length > 0) {
+                for (let i of extused) {
                     subst.tool = i;
                     appendSubPad(line);
                 }
diff --git a/src/mode/fdm/prepare.js b/src/mode/fdm/prepare.js
index 36fdef63..5e15a680 100644
--- a/src/mode/fdm/prepare.js
+++ b/src/mode/fdm/prepare.js
@@ -228,7 +228,7 @@
 
         let lastPoly;
         let lastLayer;
-        let extruders = [];
+        let extruders = print.extruders = [];
         let extcount = 0;
 
         // find max layers (for updates)