diff --git a/contracts/zkllvm/circuit1/commitment.sol b/contracts/zkllvm/circuit1/commitment.sol
index a8ce01a..3fa52dc 100644
--- a/contracts/zkllvm/circuit1/commitment.sol
+++ b/contracts/zkllvm/circuit1/commitment.sol
@@ -453,8 +453,9 @@ library modular_commitment_scheme_circuit1 {
             
         bytes calldata proof_of_work = blob[blob.length - 4:];
         transcript.update_transcript(tr_state, proof_of_work);
-        transcript.get_integral_challenge_be(tr_state, 4);
-            
+        uint256 p_o_w = transcript.get_integral_challenge_be(tr_state, 4);
+        if (p_o_w & 4294901760 != 0) return false;
+
                         
             unchecked{
                 offset += 0x8 + r;
@@ -586,4 +587,4 @@ library modular_commitment_scheme_circuit1 {
         return true;
     }
 }        
-    
\ No newline at end of file
+    
diff --git a/contracts/zkllvm/circuit2/commitment.sol b/contracts/zkllvm/circuit2/commitment.sol
index 2f13324..d01f9fa 100644
--- a/contracts/zkllvm/circuit2/commitment.sol
+++ b/contracts/zkllvm/circuit2/commitment.sol
@@ -585,4 +585,4 @@ library modular_commitment_scheme_circuit2 {
         return true;
     }
 }        
-    
\ No newline at end of file
+    
diff --git a/contracts/zkllvm/circuit3/commitment.sol b/contracts/zkllvm/circuit3/commitment.sol
index cfc1c94..9c59646 100644
--- a/contracts/zkllvm/circuit3/commitment.sol
+++ b/contracts/zkllvm/circuit3/commitment.sol
@@ -457,8 +457,9 @@ library modular_commitment_scheme_circuit3 {
             
         bytes calldata proof_of_work = blob[blob.length - 4:];
         transcript.update_transcript(tr_state, proof_of_work);
-        transcript.get_integral_challenge_be(tr_state, 4);
-            
+        uint256 p_o_w = transcript.get_integral_challenge_be(tr_state, 4);
+        if (p_o_w & 4294901760 != 0) return false;
+
                         
             unchecked{
                 offset += 0x8 + r;
diff --git a/contracts/zkllvm/circuit4/commitment.sol b/contracts/zkllvm/circuit4/commitment.sol
index 0273f8d..40ccf7f 100644
--- a/contracts/zkllvm/circuit4/commitment.sol
+++ b/contracts/zkllvm/circuit4/commitment.sol
@@ -457,8 +457,9 @@ library modular_commitment_scheme_circuit4 {
             
         bytes calldata proof_of_work = blob[blob.length - 4:];
         transcript.update_transcript(tr_state, proof_of_work);
-        transcript.get_integral_challenge_be(tr_state, 4);
-            
+        uint256 p_o_w = transcript.get_integral_challenge_be(tr_state, 4);
+        if (p_o_w & 4294901760 != 0) return false;
+
                         
             unchecked{
                 offset += 0x8 + r;
diff --git a/contracts/zkllvm/circuit6/commitment.sol b/contracts/zkllvm/circuit6/commitment.sol
index 100e30a..dd44fb8 100644
--- a/contracts/zkllvm/circuit6/commitment.sol
+++ b/contracts/zkllvm/circuit6/commitment.sol
@@ -460,8 +460,9 @@ library modular_commitment_scheme_circuit6 {
             
         bytes calldata proof_of_work = blob[blob.length - 4:];
         transcript.update_transcript(tr_state, proof_of_work);
-        transcript.get_integral_challenge_be(tr_state, 4);
-            
+        uint256 p_o_w = transcript.get_integral_challenge_be(tr_state, 4);
+        if (p_o_w & 4294901760 != 0) return false;
+
                         
             unchecked{
                 offset += 0x8 + r;