diff --git a/evm/src/cpu/columns.rs b/evm/src/cpu/columns.rs
index 5523fa7c..3c90c673 100644
--- a/evm/src/cpu/columns.rs
+++ b/evm/src/cpu/columns.rs
@@ -161,10 +161,10 @@ pub const SIMPLE_LOGIC_DIFF_INV: usize = SIMPLE_LOGIC_DIFF + 1;
 const NUM_MEMORY_OPS: usize = 4;
 const NUM_MEMORY_VALUE_LIMBS: usize = 8;
 
-pub(crate) const MEMORY_TIMESTAMP: usize = SIMPLE_LOGIC_DIFF_INV + 1;
+pub(crate) const CLOCK: usize = SIMPLE_LOGIC_DIFF_INV + 1;
 
 
-const USES_MEMOP_START: usize = MEMORY_TIMESTAMP + 1;
+const USES_MEMOP_START: usize = CLOCK + 1;
 pub const fn uses_memop(op: usize) -> usize {
     debug_assert!(op < NUM_MEMORY_OPS);
     USES_MEMOP_START + op