diff --git a/crates/e2e_test/src/distributed_startup_regression_test.rs b/crates/e2e_test/src/distributed_startup_regression_test.rs
index 3389eb876..ebe98d5a2 100644
--- a/crates/e2e_test/src/distributed_startup_regression_test.rs
+++ b/crates/e2e_test/src/distributed_startup_regression_test.rs
@@ -399,7 +399,7 @@ mod tests {
             }
             hash.update(&buf[..len]);
         }
-        Ok(format!("{:x}", hash.finalize()))
+        Ok(rustfs_utils::crypto::hex(hash.finalize()))
     }
 
     fn startup_cas_git(args: &[&str]) -> std::io::Result<String> {
diff --git a/crates/ecstore/src/core/pools.rs b/crates/ecstore/src/core/pools.rs
index 3854b2933..dc941b20c 100644
--- a/crates/ecstore/src/core/pools.rs
+++ b/crates/ecstore/src/core/pools.rs
@@ -5519,7 +5519,7 @@ where
     let observation = std::env::var_os("RUSTFS_E2E_STARTUP_CAS_NONCE").map(|_| {
         serde_json::json!({
             "kind": "cas", "object": object, "phase": phase,
-            "payload_sha256": format!("{:x}", Sha256::digest(&data)),
+            "payload_sha256": rustfs_utils::crypto::hex(Sha256::digest(&data)),
             "if_match": opts.http_preconditions.as_ref().and_then(|p| p.if_match.as_deref()),
             "if_none_match": opts.http_preconditions.as_ref().and_then(|p| p.if_none_match.as_deref()),
             "tail_drained": opts.write_completion == crate::object_api::WriteCompletion::TailDrained,
@@ -6843,7 +6843,7 @@ impl PoolMeta {
             #[cfg(feature = "e2e-test-hooks")]
             startup_cas_test_observe(serde_json::json!({
                 "kind": "confirmed", "object": POOL_META_NAME,
-                "payload_sha256": format!("{:x}", Sha256::digest(&durable)),
+                "payload_sha256": rustfs_utils::crypto::hex(Sha256::digest(&durable)),
                 "generation": confirmed.revision.generation,
                 "transaction_id": confirmed.revision.transaction_id,
             }));
diff --git a/rustfs/src/storage/rpc/node_service/disk.rs b/rustfs/src/storage/rpc/node_service/disk.rs
index e8a7ee4fd..fb237b31c 100644
--- a/rustfs/src/storage/rpc/node_service/disk.rs
+++ b/rustfs/src/storage/rpc/node_service/disk.rs
@@ -56,7 +56,7 @@ fn startup_cas_rename_observation(
         "target": match target { LocalMutationTarget::Ready(_) => "ready", LocalMutationTarget::Bootstrap(_) => "bootstrap", LocalMutationTarget::Unbound => "unbound" },
         "disk": request.disk, "src_volume": request.src_volume, "src_path": request.src_path,
         "dst_volume": request.dst_volume, "dst_path": request.dst_path,
-        "body_sha256": format!("{:x}", Sha256::digest(body)),
+        "body_sha256": rustfs_utils::crypto::hex(Sha256::digest(body)),
         "etag": file_info.metadata.get("etag"),
         "mod_time": file_info.mod_time.map(|time| time.unix_timestamp_nanos().to_string()),
     }))