diff --git a/evm/src/cpu/memio.rs b/evm/src/cpu/memio.rs
index 3fcdfc96..6ea82089 100644
--- a/evm/src/cpu/memio.rs
+++ b/evm/src/cpu/memio.rs
@@ -43,6 +43,15 @@ fn eval_packed_load<P: PackedField>(
     yield_constr.constraint(filter * (load_channel.addr_segment - addr_segment));
     yield_constr.constraint(filter * (load_channel.addr_virtual - addr_virtual));
 
+    // Constrain the new top of the stack.
+    for (&limb_loaded, &limb_new_top) in load_channel
+        .value
+        .iter()
+        .zip(nv.mem_channels[0].value.iter())
+    {
+        yield_constr.constraint(filter * (limb_loaded - limb_new_top));
+    }
+
     // Disable remaining memory channels, if any.
     for &channel in &lv.mem_channels[4..NUM_GP_CHANNELS] {
         yield_constr.constraint(filter * channel.used);
@@ -95,6 +104,17 @@ fn eval_ext_circuit_load<F: RichField + Extendable<D>, const D: usize>(
         yield_constr.constraint(builder, constr);
     }
 
+    // Constrain the new top of the stack.
+    for (&limb_loaded, &limb_new_top) in load_channel
+        .value
+        .iter()
+        .zip(nv.mem_channels[0].value.iter())
+    {
+        let diff = builder.sub_extension(limb_loaded, limb_new_top);
+        let constr = builder.mul_extension(filter, diff);
+        yield_constr.constraint(builder, constr);
+    }
+
     // Disable remaining memory channels, if any.
     for &channel in &lv.mem_channels[4..] {
         let constr = builder.mul_extension(filter, channel.used);