diff --git a/ceno_zkvm/src/structs.rs b/ceno_zkvm/src/structs.rs
index 0e8d8d122..b89a8ecdb 100644
--- a/ceno_zkvm/src/structs.rs
+++ b/ceno_zkvm/src/structs.rs
@@ -49,7 +49,7 @@ pub enum ROMType {
     Or,          // a | b where a, b are bytes
     Xor,         // a ^ b where a, b are bytes
     Ltu,         // a <(usign) b where a, b are bytes and the result is 0/1.
-    Pow,         // a ** b where a is a 5-bit number
+    Pow,         // a ** b where a is 2 and b is 5-bit value
     Instruction, // Decoded instruction from the fixed program.
 }
 
diff --git a/ceno_zkvm/src/tables/ops.rs b/ceno_zkvm/src/tables/ops.rs
index 7ae004212..3dc8fc46a 100644
--- a/ceno_zkvm/src/tables/ops.rs
+++ b/ceno_zkvm/src/tables/ops.rs
@@ -83,13 +83,10 @@ pub struct PowTable;
 impl OpsTable for PowTable {
     const ROM_TYPE: ROMType = ROMType::Pow;
     fn len() -> usize {
-        (1 << 5) + 1
+        1 << 5
     }
 
     fn content() -> Vec<[u64; 3]> {
-        (0..Self::len() as u64)
-            .map(|b| [2, b, 1 << b])
-            .chain(std::iter::once([0, 0, 0]))
-            .collect()
+        (0..Self::len() as u64).map(|b| [2, b, 1 << b]).collect()
     }
 }