diff --git a/evm/src/witness/operation.rs b/evm/src/witness/operation.rs
index 43576ff4..8ed0e551 100644
--- a/evm/src/witness/operation.rs
+++ b/evm/src/witness/operation.rs
@@ -11,7 +11,9 @@ use crate::cpu::membus::NUM_GP_CHANNELS;
 use crate::cpu::simple_logic::eq_iszero::generate_pinv_diff;
 use crate::generation::state::GenerationState;
 use crate::memory::segments::Segment;
+use crate::witness::errors::MemoryError::{ContextTooLarge, SegmentTooLarge, VirtTooLarge};
 use crate::witness::errors::ProgramError;
+use crate::witness::errors::ProgramError::MemoryError;
 use crate::witness::memory::{MemoryAddress, MemoryOp};
 use crate::witness::util::{
     keccak_sponge_log, mem_read_gp_with_log_and_fill, mem_write_gp_log_and_fill,
@@ -632,9 +634,15 @@ pub(crate) fn generate_mstore_general<F: Field>(
         stack_pop_with_log_and_fill::<4, _>(state, &mut row)?;
 
     let address = MemoryAddress {
-        context: context.as_usize(),
-        segment: segment.as_usize(),
-        virt: virt.as_usize(),
+        context: context
+            .try_into()
+            .map_err(|_| MemoryError(ContextTooLarge { context }))?,
+        segment: segment
+            .try_into()
+            .map_err(|_| MemoryError(SegmentTooLarge { segment }))?,
+        virt: virt
+            .try_into()
+            .map_err(|_| MemoryError(VirtTooLarge { virt }))?,
     };
     let log_write = mem_write_gp_log_and_fill(4, address, state, &mut row, val);