diff --git a/projects/common/src/main/java/dan200/computercraft/shared/lectern/CustomLecternBlockEntity.java b/projects/common/src/main/java/dan200/computercraft/shared/lectern/CustomLecternBlockEntity.java
index 7e5e3ed32..e091214c1 100644
--- a/projects/common/src/main/java/dan200/computercraft/shared/lectern/CustomLecternBlockEntity.java
+++ b/projects/common/src/main/java/dan200/computercraft/shared/lectern/CustomLecternBlockEntity.java
@@ -4,6 +4,7 @@
 
 package dan200.computercraft.shared.lectern;
 
+import dan200.computercraft.annotations.ForgeOverride;
 import dan200.computercraft.api.peripheral.IPeripheral;
 import dan200.computercraft.core.computer.ComputerSide;
 import dan200.computercraft.shared.ModRegistry;
@@ -35,6 +36,7 @@ import net.minecraft.world.level.block.LecternBlock;
 import net.minecraft.world.level.block.entity.BlockEntity;
 import net.minecraft.world.level.block.entity.LecternBlockEntity;
 import net.minecraft.world.level.block.state.BlockState;
+import net.minecraft.world.phys.AABB;
 import org.jspecify.annotations.Nullable;
 
 import java.util.AbstractList;
@@ -181,6 +183,12 @@ public final class CustomLecternBlockEntity extends BlockEntity {
         }
     }
 
+    @ForgeOverride
+    public AABB getRenderBoundingBox() {
+        var pos = getBlockPos();
+        return new AABB(pos.getX(), pos.getY(), pos.getZ(), pos.getX() + 1.0, pos.getY() + 1.5, pos.getZ() + 1.0);
+    }
+
     /**
      * A read-only container storing the lectern's contents.
      */
diff --git a/projects/common/src/main/java/dan200/computercraft/shared/peripheral/monitor/MonitorBlockEntity.java b/projects/common/src/main/java/dan200/computercraft/shared/peripheral/monitor/MonitorBlockEntity.java
index 6df370e21..7d44c297c 100644
--- a/projects/common/src/main/java/dan200/computercraft/shared/peripheral/monitor/MonitorBlockEntity.java
+++ b/projects/common/src/main/java/dan200/computercraft/shared/peripheral/monitor/MonitorBlockEntity.java
@@ -524,7 +524,7 @@ public class MonitorBlockEntity extends BlockEntity {
         bbHeight = height;
 
         var startPos = toWorldPos(0, 0);
-        var endPos = toWorldPos(width, height);
+        var endPos = toWorldPos(width - 1, height - 1);
         return boundingBox = new AABB(
             Math.min(startPos.getX(), endPos.getX()),
             Math.min(startPos.getY(), endPos.getY()),