diff --git a/plate-tool-eframe/src/plate.rs b/plate-tool-eframe/src/plate.rs
index e941e95..382b912 100644
--- a/plate-tool-eframe/src/plate.rs
+++ b/plate-tool-eframe/src/plate.rs
@@ -148,12 +148,14 @@ fn calculate_shading_for_wells(
                     x.volume += 5.0;
                     x.color = PALETTE.get_ordered(transfer.id, ordered_ids);
                 } else {
-                    well_infos
-                        [(well.row - 1) as usize * columns as usize + (well.col - 1) as usize] =
-                        Some(WellInfo::new(
+                    if let Some(mut wi) = well_infos.get_mut(
+                        (well.row - 1) as usize * columns as usize + (well.col - 1) as usize,
+                    ) {
+                        *wi = Some(WellInfo::new(
                             5.0,
                             PALETTE.get_ordered(transfer.id, ordered_ids),
                         ));
+                    }
                 }
             }
         }
@@ -276,17 +278,20 @@ fn add_plate_sub(
         };
         if let Some(wells) = current_transfer_wells {
             for w in wells {
-                let well_info = &mut well_infos[(w.0 - 1) * columns as usize + (w.1 - 1)];
-                let volume = well_info.map(|x| x.volume).unwrap_or(0.0)
-                    + current_transfer_state
-                        .and_then(|x| x.lock().ok())
-                        .map(|x| x.volume)
-                        .unwrap_or(0.0);
+                if let Some(mut well_info) =
+                    well_infos.get_mut((w.0 - 1) * columns as usize + (w.1 - 1))
+                {
+                    let volume = well_info.map(|x| x.volume).unwrap_or(0.0)
+                        + current_transfer_state
+                            .and_then(|x| x.lock().ok())
+                            .map(|x| x.volume)
+                            .unwrap_or(0.0);
 
-                *well_info = Some(WellInfo {
-                    color: [255.0, 255.0, 255.0],
-                    volume: 1.0,
-                })
+                    *well_info = Some(WellInfo {
+                        color: [255.0, 255.0, 255.0],
+                        volume: 1.0,
+                    })
+                }
             }
         }
         well_infos