diff --git a/protocol-designer/src/steplist/formLevel/handleFormChange/dependentFieldsUpdateMoveLiquid.ts b/protocol-designer/src/steplist/formLevel/handleFormChange/dependentFieldsUpdateMoveLiquid.ts
index e40486135dc..752a6629386 100644
--- a/protocol-designer/src/steplist/formLevel/handleFormChange/dependentFieldsUpdateMoveLiquid.ts
+++ b/protocol-designer/src/steplist/formLevel/handleFormChange/dependentFieldsUpdateMoveLiquid.ts
@@ -514,10 +514,10 @@ const updatePatchOnPipetteChannelChange = (
   const multiToSingle =
     (prevChannels === 8 || prevChannels === 96) && nextChannels === 1
 
+  const pipetteId: string = appliedPatch.pipette as string
+
   if (patch.pipette === null || singleToMulti) {
     // reset all well selection
-    // @ts-expect-error(sa, 2021-6-14): appliedPatch.pipette does not exist. Address in #3161
-    const pipetteId: string = appliedPatch.pipette
     update = {
       aspirate_wells: getDefaultWells({
         // @ts-expect-error(sa, 2021-6-14): appliedPatch.aspirate_labware does not exist. Address in #3161
@@ -545,18 +545,27 @@ const updatePatchOnPipetteChannelChange = (
     const sourceLabware = labwareEntities[sourceLabwareId]
     const sourceLabwareDef = sourceLabware.def
     const destLabware = labwareEntities[destLabwareId]
-    const destLabwareDef = destLabware.def
+
     update = {
       aspirate_wells: getAllWellsFromPrimaryWells(
         appliedPatch.aspirate_wells as string[],
         sourceLabwareDef,
         channels as 8 | 96
       ),
-      dispense_wells: getAllWellsFromPrimaryWells(
-        appliedPatch.dispense_wells as string[],
-        destLabwareDef,
-        channels as 8 | 96
-      ),
+      dispense_wells:
+        destLabwareId.includes('trashBin') ||
+        destLabwareId.includes('wasteChute')
+          ? getDefaultWells({
+              labwareId: destLabwareId,
+              pipetteId,
+              labwareEntities,
+              pipetteEntities,
+            })
+          : getAllWellsFromPrimaryWells(
+              appliedPatch.dispense_wells as string[],
+              destLabware.def,
+              channels as 8 | 96
+            ),
     }
   }