diff --git a/packages/codemirror/slider.mjs b/packages/codemirror/slider.mjs
index 63015051..2e75959b 100644
--- a/packages/codemirror/slider.mjs
+++ b/packages/codemirror/slider.mjs
@@ -152,6 +152,6 @@ function updateSliderValue(view, e) {
   let change = { from: draggedSlider.from, to: draggedSlider.to, insert };
   draggedSlider.to = draggedSlider.from + insert.length;
   view.dispatch({ changes: change });
-  window.postMessage({ type: 'slider-change', value: next });
+  window.postMessage({ type: 'cm-slider', value: next, loc: draggedSlider.from });
   return true;
 }
diff --git a/packages/transpiler/transpiler.mjs b/packages/transpiler/transpiler.mjs
index 78aae9f7..9ff558cb 100644
--- a/packages/transpiler/transpiler.mjs
+++ b/packages/transpiler/transpiler.mjs
@@ -35,6 +35,10 @@ export function transpiler(input, options = {}) {
         emitMiniLocations && collectMiniLocations(value, node);
         return this.replace(miniWithLocation(value, node));
       }
+      if (isWidgetFunction(node)) {
+        // collectSliderLocations?
+        return this.replace(widgetWithLocation(node));
+      }
       // TODO: remove pseudo note variables?
       if (node.type === 'Identifier' && isNoteWithOctave(node.name)) {
         this.skip();
@@ -68,11 +72,10 @@ export function transpiler(input, options = {}) {
 }
 
 function isStringWithDoubleQuotes(node, locations, code) {
-  const { raw, type } = node;
-  if (type !== 'Literal') {
+  if (node.type !== 'Literal') {
     return false;
   }
-  return raw[0] === '"';
+  return node.raw[0] === '"';
 }
 
 function isBackTickString(node, parent) {
@@ -94,3 +97,19 @@ function miniWithLocation(value, node) {
     optional: false,
   };
 }
+
+function isWidgetFunction(node) {
+  return node.type === 'CallExpression' && node.callee.name === 'slider';
+}
+
+function widgetWithLocation(node) {
+  const loc = node.arguments[0].start;
+  // add loc as identifier to first argument
+  // the slider function is assumed to be slider(loc, value, min?, max?)
+  node.arguments.unshift({
+    type: 'Literal',
+    value: loc,
+    raw: loc + '',
+  });
+  return node;
+}