diff --git a/crates/e2e_test/src/kms/bucket_default_encryption_test.rs b/crates/e2e_test/src/kms/bucket_default_encryption_test.rs
index fecba2b89..c0f0f0181 100644
--- a/crates/e2e_test/src/kms/bucket_default_encryption_test.rs
+++ b/crates/e2e_test/src/kms/bucket_default_encryption_test.rs
@@ -37,7 +37,7 @@ async fn test_bucket_default_sse_s3_put_object() -> Result<(), Box<dyn std::erro
 
     let mut kms_env = LocalKMSTestEnvironment::new().await?;
     let _default_key_id = kms_env.start_rustfs_for_local_kms().await?;
-    tokio::time::sleep(tokio::time::Duration::from_secs(3)).await;
+    kms_env.wait_for_kms_ready().await?;
 
     let s3_client = kms_env.base_env.create_s3_client();
     kms_env.base_env.create_test_bucket(TEST_BUCKET).await?;
@@ -159,7 +159,7 @@ async fn test_bucket_default_sse_kms_put_object() -> Result<(), Box<dyn std::err
 
     let mut kms_env = LocalKMSTestEnvironment::new().await?;
     let default_key_id = kms_env.start_rustfs_for_local_kms().await?;
-    tokio::time::sleep(tokio::time::Duration::from_secs(3)).await;
+    kms_env.wait_for_kms_ready().await?;
 
     let s3_client = kms_env.base_env.create_s3_client();
     kms_env.base_env.create_test_bucket(TEST_BUCKET).await?;
@@ -278,7 +278,7 @@ async fn test_bucket_default_sse_kms_multipart_crc32() -> Result<(), Box<dyn std
 
     let mut kms_env = LocalKMSTestEnvironment::new().await?;
     let default_key_id = kms_env.start_rustfs_for_local_kms().await?;
-    tokio::time::sleep(tokio::time::Duration::from_secs(3)).await;
+    kms_env.wait_for_kms_ready().await?;
 
     let s3_client = kms_env.base_env.create_s3_client();
     kms_env.base_env.create_test_bucket(TEST_BUCKET).await?;
@@ -475,7 +475,7 @@ async fn test_explicit_encryption_overrides_bucket_default() -> Result<(), Box<d
 
     let mut kms_env = LocalKMSTestEnvironment::new().await?;
     let default_key_id = kms_env.start_rustfs_for_local_kms().await?;
-    tokio::time::sleep(tokio::time::Duration::from_secs(3)).await;
+    kms_env.wait_for_kms_ready().await?;
 
     let s3_client = kms_env.base_env.create_s3_client();
     kms_env.base_env.create_test_bucket(TEST_BUCKET).await?;
@@ -570,7 +570,7 @@ async fn test_sse_kms_without_key_id_populates_default() -> Result<(), Box<dyn s
 
     let mut kms_env = LocalKMSTestEnvironment::new().await?;
     let default_key_id = kms_env.start_rustfs_for_local_kms().await?;
-    tokio::time::sleep(tokio::time::Duration::from_secs(3)).await;
+    kms_env.wait_for_kms_ready().await?;
 
     let s3_client = kms_env.base_env.create_s3_client();
     kms_env.base_env.create_test_bucket(TEST_BUCKET).await?;
diff --git a/crates/e2e_test/src/kms/common.rs b/crates/e2e_test/src/kms/common.rs
index 290cb937d..07b21db4d 100644
--- a/crates/e2e_test/src/kms/common.rs
+++ b/crates/e2e_test/src/kms/common.rs
@@ -189,34 +189,121 @@ pub async fn wait_for_kms_ready(
     access_key: &str,
     secret_key: &str,
 ) -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
-    let total_deadline = Duration::from_secs(5);
+    wait_for_kms_ready_with_timeout(base_url, access_key, secret_key, Duration::from_secs(5)).await
+}
+
+async fn wait_for_kms_ready_with_timeout(
+    base_url: &str,
+    access_key: &str,
+    secret_key: &str,
+    total_deadline: Duration,
+) -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
     let start = tokio::time::Instant::now();
+    let deadline = start + total_deadline;
     let mut backoff = Duration::from_millis(200);
     let max_backoff = Duration::from_secs(1);
-    let mut first_attempt = true;
 
     loop {
-        if !first_attempt {
-            if start.elapsed() >= total_deadline {
-                return Err("KMS failed to become ready within 5 seconds".into());
-            }
-            sleep(backoff).await;
-            backoff = (backoff * 2).min(max_backoff);
-        }
-        first_attempt = false;
-
-        match get_kms_status(base_url, access_key, secret_key).await {
-            Ok(status) => {
-                info!("KMS is ready (status: {})", status);
-                return Ok(());
-            }
-            Err(e) => {
-                if start.elapsed() >= total_deadline {
-                    return Err(format!("KMS did not become ready within 5 s: last error: {e}").into());
+        match tokio::time::timeout_at(deadline, get_kms_status(base_url, access_key, secret_key)).await {
+            Ok(Ok(status)) => {
+                let backend_status = serde_json::from_str::<serde_json::Value>(&status)
+                    .ok()
+                    .and_then(|value| value.get("backend_status")?.as_str().map(str::to_owned));
+                if backend_status.as_deref() == Some("healthy") {
+                    info!("KMS is ready (status: {})", status);
+                    return Ok(());
                 }
-                warn!(error = %e, elapsed_ms = start.elapsed().as_millis() as u64, "KMS not ready yet, retrying…");
+                warn!(
+                    backend_status = backend_status.as_deref().unwrap_or("missing"),
+                    elapsed_ms = u64::try_from(start.elapsed().as_millis()).unwrap_or(u64::MAX),
+                    "KMS not ready yet, retrying…"
+                );
             }
+            Ok(Err(e)) => {
+                let elapsed_ms = u64::try_from(start.elapsed().as_millis()).unwrap_or(u64::MAX);
+                warn!(error = %e, elapsed_ms, "KMS not ready yet, retrying…");
+            }
+            Err(_) => return Err(format!("KMS failed to become ready within {} ms", total_deadline.as_millis()).into()),
         }
+
+        let now = tokio::time::Instant::now();
+        if now >= deadline {
+            return Err(format!("KMS failed to become ready within {} ms", total_deadline.as_millis()).into());
+        }
+        sleep((now + backoff).min(deadline) - now).await;
+        backoff = (backoff * 2).min(max_backoff);
+    }
+}
+
+#[cfg(test)]
+mod readiness_tests {
+    use super::{wait_for_kms_ready, wait_for_kms_ready_with_timeout};
+    use std::sync::{
+        Arc,
+        atomic::{AtomicUsize, Ordering},
+    };
+    use std::time::Duration;
+    use tokio::io::{AsyncReadExt, AsyncWriteExt};
+    use tokio::net::TcpListener;
+
+    #[tokio::test]
+    async fn kms_readiness_retries_http_success_until_backend_is_healthy() {
+        let listener = TcpListener::bind("127.0.0.1:0").await.expect("bind readiness test server");
+        let address = listener.local_addr().expect("read readiness test server address");
+        let requests = Arc::new(AtomicUsize::new(0));
+        let server_requests = Arc::clone(&requests);
+        let server = tokio::spawn(async move {
+            for backend_status in ["error", "healthy"] {
+                let (mut socket, _) = listener.accept().await.expect("accept readiness request");
+                let mut request = Vec::new();
+                let mut chunk = [0_u8; 1024];
+                while !request.windows(4).any(|window| window == b"\r\n\r\n") {
+                    let read = socket.read(&mut chunk).await.expect("read readiness request");
+                    if read == 0 {
+                        break;
+                    }
+                    request.extend_from_slice(&chunk[..read]);
+                }
+                server_requests.fetch_add(1, Ordering::SeqCst);
+
+                let body = format!(r#"{{"backend_status":"{backend_status}"}}"#);
+                let response = format!(
+                    "HTTP/1.1 200 OK\r\nContent-Type: application/json\r\nContent-Length: {}\r\nConnection: close\r\n\r\n{body}",
+                    body.len()
+                );
+                socket.write_all(response.as_bytes()).await.expect("write readiness response");
+            }
+        });
+
+        wait_for_kms_ready(&format!("http://{address}"), "access-key", "secret-key")
+            .await
+            .expect("KMS should become ready after the healthy response");
+
+        let observed_requests = requests.load(Ordering::SeqCst);
+        server.abort();
+        assert_eq!(observed_requests, 2, "an HTTP 200 unhealthy status must be retried");
+    }
+
+    #[tokio::test]
+    async fn kms_readiness_deadline_covers_a_stalled_status_request() {
+        let listener = TcpListener::bind("127.0.0.1:0").await.expect("bind readiness test server");
+        let address = listener.local_addr().expect("read readiness test server address");
+        let server = tokio::spawn(async move {
+            let (mut socket, _) = listener.accept().await.expect("accept readiness request");
+            let mut request = [0_u8; 1024];
+            let _ = socket.read(&mut request).await.expect("read readiness request");
+            std::future::pending::<()>().await;
+        });
+
+        let result = tokio::time::timeout(
+            Duration::from_secs(1),
+            wait_for_kms_ready_with_timeout(&format!("http://{address}"), "access-key", "secret-key", Duration::from_millis(50)),
+        )
+        .await
+        .expect("readiness helper must enforce its own deadline");
+
+        server.abort();
+        assert!(result.is_err(), "a stalled status request must not outlive the readiness deadline");
     }
 }
 
diff --git a/crates/e2e_test/src/kms/copy_object_self_copy_sse_test.rs b/crates/e2e_test/src/kms/copy_object_self_copy_sse_test.rs
index 1cf19a565..85a013ab3 100644
--- a/crates/e2e_test/src/kms/copy_object_self_copy_sse_test.rs
+++ b/crates/e2e_test/src/kms/copy_object_self_copy_sse_test.rs
@@ -61,7 +61,7 @@ async fn test_metadata_replace_self_copy_of_sse_object_stays_decryptable() {
         )
         .await
         .expect("failed to start RustFS with local KMS");
-    tokio::time::sleep(tokio::time::Duration::from_secs(3)).await;
+    kms_env.wait_for_kms_ready().await.expect("KMS ready");
 
     let client = kms_env.base_env.create_s3_client();
     // Deliberately an UNVERSIONED bucket: that is the branch where the store layer can service
@@ -160,7 +160,7 @@ async fn test_metadata_replace_self_copy_dropping_sse_rewrites_plaintext() {
         )
         .await
         .expect("failed to start RustFS with local KMS");
-    tokio::time::sleep(tokio::time::Duration::from_secs(3)).await;
+    kms_env.wait_for_kms_ready().await.expect("KMS ready");
 
     let client = kms_env.base_env.create_s3_client();
     // Unversioned, and deliberately WITHOUT a bucket default-encryption rule, so the copy below
@@ -256,7 +256,7 @@ async fn test_metadata_replace_self_copy_under_bucket_default_sse_stays_decrypta
         )
         .await
         .expect("failed to start RustFS with local KMS");
-    tokio::time::sleep(tokio::time::Duration::from_secs(3)).await;
+    kms_env.wait_for_kms_ready().await.expect("KMS ready");
 
     let client = kms_env.base_env.create_s3_client();
     let bucket = "copy-object-self-copy-bucket-default-sse-test";
diff --git a/crates/e2e_test/src/kms/copy_object_version_restore_sse_test.rs b/crates/e2e_test/src/kms/copy_object_version_restore_sse_test.rs
index 3241a217d..c7a572e93 100644
--- a/crates/e2e_test/src/kms/copy_object_version_restore_sse_test.rs
+++ b/crates/e2e_test/src/kms/copy_object_version_restore_sse_test.rs
@@ -56,7 +56,7 @@ async fn test_self_copy_of_historical_sse_s3_version_is_readable() {
         )
         .await
         .expect("failed to start RustFS with local KMS");
-    tokio::time::sleep(tokio::time::Duration::from_secs(3)).await;
+    kms_env.wait_for_kms_ready().await.expect("KMS ready");
 
     let client = kms_env.base_env.create_s3_client();
     let bucket = "copy-object-version-restore-sse-test";
diff --git a/crates/e2e_test/src/kms/encryption_metadata_test.rs b/crates/e2e_test/src/kms/encryption_metadata_test.rs
index a316668f6..59501430b 100644
--- a/crates/e2e_test/src/kms/encryption_metadata_test.rs
+++ b/crates/e2e_test/src/kms/encryption_metadata_test.rs
@@ -87,7 +87,7 @@ async fn test_head_reports_managed_metadata_for_sse_s3() -> Result<(), Box<dyn s
 
     let mut kms_env = LocalKMSTestEnvironment::new().await?;
     let _default_key = kms_env.start_rustfs_for_local_kms().await?;
-    tokio::time::sleep(tokio::time::Duration::from_secs(3)).await;
+    kms_env.wait_for_kms_ready().await?;
 
     let s3_client = kms_env.base_env.create_s3_client();
     kms_env.base_env.create_test_bucket(TEST_BUCKET).await?;
@@ -147,7 +147,7 @@ async fn test_head_reports_managed_metadata_for_sse_kms_and_copy() -> Result<(),
 
     let mut kms_env = LocalKMSTestEnvironment::new().await?;
     let default_key_id = kms_env.start_rustfs_for_local_kms().await?;
-    tokio::time::sleep(tokio::time::Duration::from_secs(3)).await;
+    kms_env.wait_for_kms_ready().await?;
 
     let s3_client = kms_env.base_env.create_s3_client();
     kms_env.base_env.create_test_bucket(TEST_BUCKET).await?;
@@ -250,7 +250,7 @@ async fn test_multipart_upload_writes_encrypted_data() -> Result<(), Box<dyn std
 
     let mut kms_env = LocalKMSTestEnvironment::new().await?;
     let default_key_id = kms_env.start_rustfs_for_local_kms().await?;
-    tokio::time::sleep(tokio::time::Duration::from_secs(3)).await;
+    kms_env.wait_for_kms_ready().await?;
 
     let s3_client = kms_env.base_env.create_s3_client();
     kms_env.base_env.create_test_bucket(TEST_BUCKET).await?;
diff --git a/crates/e2e_test/src/kms/kms_comprehensive_test.rs b/crates/e2e_test/src/kms/kms_comprehensive_test.rs
index 584ae64eb..9ec1087a3 100644
--- a/crates/e2e_test/src/kms/kms_comprehensive_test.rs
+++ b/crates/e2e_test/src/kms/kms_comprehensive_test.rs
@@ -24,7 +24,6 @@ use super::common::{
     test_sse_kms_encryption, test_sse_s3_encryption,
 };
 use crate::common::{TEST_BUCKET, init_logging};
-use tokio::time::{Duration, sleep};
 use tracing::info;
 
 /// Comprehensive test: Full KMS workflow with all encryption types
@@ -35,7 +34,7 @@ async fn test_comprehensive_kms_full_workflow() -> Result<(), Box<dyn std::error
 
     let mut kms_env = LocalKMSTestEnvironment::new().await?;
     let _default_key_id = kms_env.start_rustfs_for_local_kms().await?;
-    sleep(Duration::from_secs(3)).await;
+    kms_env.wait_for_kms_ready().await?;
 
     let s3_client = kms_env.base_env.create_s3_client();
     kms_env.base_env.create_test_bucket(TEST_BUCKET).await?;
@@ -103,7 +102,7 @@ async fn test_comprehensive_stress_test() -> Result<(), Box<dyn std::error::Erro
 
     let mut kms_env = LocalKMSTestEnvironment::new().await?;
     let _default_key_id = kms_env.start_rustfs_for_local_kms().await?;
-    sleep(Duration::from_secs(3)).await;
+    kms_env.wait_for_kms_ready().await?;
 
     let s3_client = kms_env.base_env.create_s3_client();
     kms_env.base_env.create_test_bucket(TEST_BUCKET).await?;
@@ -137,7 +136,7 @@ async fn test_comprehensive_key_isolation() -> Result<(), Box<dyn std::error::Er
 
     let mut kms_env = LocalKMSTestEnvironment::new().await?;
     let _default_key_id = kms_env.start_rustfs_for_local_kms().await?;
-    sleep(Duration::from_secs(3)).await;
+    kms_env.wait_for_kms_ready().await?;
 
     let s3_client = kms_env.base_env.create_s3_client();
     kms_env.base_env.create_test_bucket(TEST_BUCKET).await?;
@@ -208,7 +207,7 @@ async fn test_comprehensive_concurrent_operations() -> Result<(), Box<dyn std::e
 
     let mut kms_env = LocalKMSTestEnvironment::new().await?;
     let _default_key_id = kms_env.start_rustfs_for_local_kms().await?;
-    sleep(Duration::from_secs(3)).await;
+    kms_env.wait_for_kms_ready().await?;
 
     let s3_client = kms_env.base_env.create_s3_client();
     kms_env.base_env.create_test_bucket(TEST_BUCKET).await?;
@@ -253,7 +252,7 @@ async fn test_comprehensive_performance_benchmark() -> Result<(), Box<dyn std::e
 
     let mut kms_env = LocalKMSTestEnvironment::new().await?;
     let _default_key_id = kms_env.start_rustfs_for_local_kms().await?;
-    sleep(Duration::from_secs(3)).await;
+    kms_env.wait_for_kms_ready().await?;
 
     let s3_client = kms_env.base_env.create_s3_client();
     kms_env.base_env.create_test_bucket(TEST_BUCKET).await?;
diff --git a/crates/e2e_test/src/kms/kms_edge_cases_test.rs b/crates/e2e_test/src/kms/kms_edge_cases_test.rs
index 9d9d1a765..b9439dee5 100644
--- a/crates/e2e_test/src/kms/kms_edge_cases_test.rs
+++ b/crates/e2e_test/src/kms/kms_edge_cases_test.rs
@@ -44,7 +44,7 @@ async fn test_kms_zero_byte_file_encryption() -> Result<(), Box<dyn std::error::
 
     let mut kms_env = LocalKMSTestEnvironment::new().await?;
     let _default_key_id = kms_env.start_rustfs_for_local_kms().await?;
-    tokio::time::sleep(tokio::time::Duration::from_secs(3)).await;
+    kms_env.wait_for_kms_ready().await?;
 
     let s3_client = kms_env.base_env.create_s3_client();
     kms_env.base_env.create_test_bucket(TEST_BUCKET).await?;
@@ -117,7 +117,7 @@ async fn test_kms_single_byte_file_encryption() -> Result<(), Box<dyn std::error
 
     let mut kms_env = LocalKMSTestEnvironment::new().await?;
     let _default_key_id = kms_env.start_rustfs_for_local_kms().await?;
-    tokio::time::sleep(tokio::time::Duration::from_secs(3)).await;
+    kms_env.wait_for_kms_ready().await?;
 
     let s3_client = kms_env.base_env.create_s3_client();
     kms_env.base_env.create_test_bucket(TEST_BUCKET).await?;
@@ -209,7 +209,7 @@ async fn test_kms_multipart_boundary_conditions() -> Result<(), Box<dyn std::err
 
     let mut kms_env = LocalKMSTestEnvironment::new().await?;
     let _default_key_id = kms_env.start_rustfs_for_local_kms().await?;
-    tokio::time::sleep(tokio::time::Duration::from_secs(3)).await;
+    kms_env.wait_for_kms_ready().await?;
 
     let s3_client = kms_env.base_env.create_s3_client();
     kms_env.base_env.create_test_bucket(TEST_BUCKET).await?;
@@ -284,7 +284,7 @@ async fn test_kms_invalid_key_scenarios() -> Result<(), Box<dyn std::error::Erro
 
     let mut kms_env = LocalKMSTestEnvironment::new().await?;
     let _default_key_id = kms_env.start_rustfs_for_local_kms().await?;
-    tokio::time::sleep(tokio::time::Duration::from_secs(3)).await;
+    kms_env.wait_for_kms_ready().await?;
 
     let s3_client = kms_env.base_env.create_s3_client();
     kms_env.base_env.create_test_bucket(TEST_BUCKET).await?;
@@ -371,7 +371,7 @@ async fn test_kms_concurrent_encryption() -> Result<(), Box<dyn std::error::Erro
 
     let mut kms_env = LocalKMSTestEnvironment::new().await?;
     let _default_key_id = kms_env.start_rustfs_for_local_kms().await?;
-    tokio::time::sleep(tokio::time::Duration::from_secs(3)).await;
+    kms_env.wait_for_kms_ready().await?;
 
     let s3_client = Arc::new(kms_env.base_env.create_s3_client());
     kms_env.base_env.create_test_bucket(TEST_BUCKET).await?;
@@ -478,7 +478,7 @@ async fn test_kms_key_validation_security() -> Result<(), Box<dyn std::error::Er
 
     let mut kms_env = LocalKMSTestEnvironment::new().await?;
     let _default_key_id = kms_env.start_rustfs_for_local_kms().await?;
-    tokio::time::sleep(tokio::time::Duration::from_secs(3)).await;
+    kms_env.wait_for_kms_ready().await?;
 
     let s3_client = kms_env.base_env.create_s3_client();
     kms_env.base_env.create_test_bucket(TEST_BUCKET).await?;
diff --git a/crates/e2e_test/src/kms/kms_fault_recovery_test.rs b/crates/e2e_test/src/kms/kms_fault_recovery_test.rs
index fa6c08170..d2942d26b 100644
--- a/crates/e2e_test/src/kms/kms_fault_recovery_test.rs
+++ b/crates/e2e_test/src/kms/kms_fault_recovery_test.rs
@@ -37,7 +37,7 @@ async fn test_kms_key_directory_unavailable() -> Result<(), Box<dyn std::error::
 
     let mut kms_env = LocalKMSTestEnvironment::new().await?;
     let _default_key_id = kms_env.start_rustfs_for_local_kms().await?;
-    tokio::time::sleep(Duration::from_secs(3)).await;
+    kms_env.wait_for_kms_ready().await?;
 
     let s3_client = kms_env.base_env.create_s3_client();
     kms_env.base_env.create_test_bucket(TEST_BUCKET).await?;
@@ -127,7 +127,7 @@ async fn test_kms_corrupted_key_files() -> Result<(), Box<dyn std::error::Error
 
     let mut kms_env = LocalKMSTestEnvironment::new().await?;
     let default_key_id = kms_env.start_rustfs_for_local_kms().await?;
-    tokio::time::sleep(Duration::from_secs(3)).await;
+    kms_env.wait_for_kms_ready().await?;
 
     let s3_client = kms_env.base_env.create_s3_client();
     kms_env.base_env.create_test_bucket(TEST_BUCKET).await?;
@@ -218,7 +218,7 @@ async fn test_kms_multipart_upload_interruption() -> Result<(), Box<dyn std::err
 
     let mut kms_env = LocalKMSTestEnvironment::new().await?;
     let _default_key_id = kms_env.start_rustfs_for_local_kms().await?;
-    tokio::time::sleep(Duration::from_secs(3)).await;
+    kms_env.wait_for_kms_ready().await?;
 
     let s3_client = kms_env.base_env.create_s3_client();
     kms_env.base_env.create_test_bucket(TEST_BUCKET).await?;
@@ -401,7 +401,7 @@ async fn test_kms_resource_constraints() -> Result<(), Box<dyn std::error::Error
 
     let mut kms_env = LocalKMSTestEnvironment::new().await?;
     let _default_key_id = kms_env.start_rustfs_for_local_kms().await?;
-    tokio::time::sleep(Duration::from_secs(3)).await;
+    kms_env.wait_for_kms_ready().await?;
 
     let s3_client = kms_env.base_env.create_s3_client();
     kms_env.base_env.create_test_bucket(TEST_BUCKET).await?;
diff --git a/crates/e2e_test/src/kms/kms_local_test.rs b/crates/e2e_test/src/kms/kms_local_test.rs
index 994a9408b..522b28478 100644
--- a/crates/e2e_test/src/kms/kms_local_test.rs
+++ b/crates/e2e_test/src/kms/kms_local_test.rs
@@ -46,7 +46,7 @@ async fn test_local_kms_end_to_end() -> Result<(), Box<dyn std::error::Error + S
         .expect("Failed to start RustFS with Local KMS");
 
     // Wait a moment for RustFS to fully start up and initialize KMS
-    tokio::time::sleep(tokio::time::Duration::from_secs(3)).await;
+    kms_env.wait_for_kms_ready().await?;
 
     info!("RustFS started with KMS auto-configuration, default_key_id: {}", default_key_id);
 
@@ -127,7 +127,7 @@ async fn test_local_kms_key_isolation() {
         .expect("Failed to start RustFS with Local KMS");
 
     // Wait a moment for RustFS to fully start up and initialize KMS
-    tokio::time::sleep(tokio::time::Duration::from_secs(3)).await;
+    kms_env.wait_for_kms_ready().await.expect("KMS ready");
 
     info!("RustFS started with KMS auto-configuration, default_key_id: {}", default_key_id);
 
@@ -227,7 +227,7 @@ async fn test_local_kms_large_file() {
         .expect("Failed to start RustFS with Local KMS");
 
     // Wait a moment for RustFS to fully start up and initialize KMS
-    tokio::time::sleep(tokio::time::Duration::from_secs(3)).await;
+    kms_env.wait_for_kms_ready().await.expect("KMS ready");
 
     info!("RustFS started with KMS auto-configuration, default_key_id: {}", default_key_id);
 
@@ -309,7 +309,7 @@ async fn test_local_kms_multipart_upload() {
         .expect("Failed to start RustFS with Local KMS");
 
     // Wait for KMS initialization
-    tokio::time::sleep(tokio::time::Duration::from_secs(3)).await;
+    kms_env.wait_for_kms_ready().await.expect("KMS ready");
 
     info!("RustFS started with KMS auto-configuration, default_key_id: {}", default_key_id);
 
diff --git a/crates/e2e_test/src/kms/kms_vault_test.rs b/crates/e2e_test/src/kms/kms_vault_test.rs
index 8fb49ca02..0dd19f703 100644
--- a/crates/e2e_test/src/kms/kms_vault_test.rs
+++ b/crates/e2e_test/src/kms/kms_vault_test.rs
@@ -19,7 +19,6 @@
 //! multipart upload behaviour.
 
 use crate::common::{TEST_BUCKET, init_logging};
-use tokio::time::{Duration, sleep};
 use tracing::{error, info};
 
 use super::common::{
@@ -45,8 +44,8 @@ impl VaultKmsTestContext {
 
         start_kms(&env.base_env.url, &env.base_env.access_key, &env.base_env.secret_key).await?;
 
-        // Allow Vault to finish initialising token auth and transit engine.
-        sleep(Duration::from_secs(2)).await;
+        // Wait for KMS to finish initialising.
+        super::common::wait_for_kms_ready(&env.base_env.url, &env.base_env.access_key, &env.base_env.secret_key).await?;
 
         Ok(Self { env })
     }
diff --git a/crates/e2e_test/src/kms/multipart_encryption_test.rs b/crates/e2e_test/src/kms/multipart_encryption_test.rs
index 10d382aa9..66a03b7b2 100644
--- a/crates/e2e_test/src/kms/multipart_encryption_test.rs
+++ b/crates/e2e_test/src/kms/multipart_encryption_test.rs
@@ -33,7 +33,7 @@ async fn test_step1_basic_single_file_encryption() -> Result<(), Box<dyn std::er
 
     let mut kms_env = LocalKMSTestEnvironment::new().await?;
     let _default_key_id = kms_env.start_rustfs_for_local_kms().await?;
-    tokio::time::sleep(tokio::time::Duration::from_secs(3)).await;
+    kms_env.wait_for_kms_ready().await?;
 
     let s3_client = kms_env.base_env.create_s3_client();
     kms_env.base_env.create_test_bucket(TEST_BUCKET).await?;
@@ -89,7 +89,7 @@ async fn test_step2_basic_multipart_upload_without_encryption() -> Result<(), Bo
 
     let mut kms_env = LocalKMSTestEnvironment::new().await?;
     let _default_key_id = kms_env.start_rustfs_for_local_kms().await?;
-    tokio::time::sleep(tokio::time::Duration::from_secs(3)).await;
+    kms_env.wait_for_kms_ready().await?;
 
     let s3_client = kms_env.base_env.create_s3_client();
     kms_env.base_env.create_test_bucket(TEST_BUCKET).await?;
@@ -187,7 +187,7 @@ async fn test_step3_multipart_upload_with_sse_s3() -> Result<(), Box<dyn std::er
 
     let mut kms_env = LocalKMSTestEnvironment::new().await?;
     let _default_key_id = kms_env.start_rustfs_for_local_kms().await?;
-    tokio::time::sleep(tokio::time::Duration::from_secs(3)).await;
+    kms_env.wait_for_kms_ready().await?;
 
     let s3_client = kms_env.base_env.create_s3_client();
     kms_env.base_env.create_test_bucket(TEST_BUCKET).await?;
@@ -310,7 +310,7 @@ async fn test_step4_large_multipart_upload_with_encryption() -> Result<(), Box<d
 
     let mut kms_env = LocalKMSTestEnvironment::new().await?;
     let _default_key_id = kms_env.start_rustfs_for_local_kms().await?;
-    tokio::time::sleep(tokio::time::Duration::from_secs(3)).await;
+    kms_env.wait_for_kms_ready().await?;
 
     let s3_client = kms_env.base_env.create_s3_client();
     kms_env.base_env.create_test_bucket(TEST_BUCKET).await?;
@@ -435,7 +435,7 @@ async fn test_step5_all_encryption_types_multipart() -> Result<(), Box<dyn std::
 
     let mut kms_env = LocalKMSTestEnvironment::new().await?;
     let _default_key_id = kms_env.start_rustfs_for_local_kms().await?;
-    tokio::time::sleep(tokio::time::Duration::from_secs(3)).await;
+    kms_env.wait_for_kms_ready().await?;
 
     let s3_client = kms_env.base_env.create_s3_client();
     kms_env.base_env.create_test_bucket(TEST_BUCKET).await?;