diff --git a/src/main/java/me/lucko/bytebin/Bytebin.java b/src/main/java/me/lucko/bytebin/Bytebin.java
index 3f6f9c5..55c34ae 100644
--- a/src/main/java/me/lucko/bytebin/Bytebin.java
+++ b/src/main/java/me/lucko/bytebin/Bytebin.java
@@ -186,7 +186,7 @@ public Bytebin(Configuration config) throws Exception {
 
         // schedule invalidation task
         if (expiryHandler.hasExpiryTimes() || metrics) {
-            this.executor.scheduleWithFixedDelay(storageHandler::runInvalidationAndRecordMetrics, 5, 60 * 5, TimeUnit.SECONDS);
+            this.executor.scheduleWithFixedDelay(storageHandler::runInvalidationAndRecordMetrics, 5, 5, TimeUnit.MINUTES);
         }
 
         if (config.getBoolean(Option.AUDIT_ON_STARTUP, false)) {
diff --git a/src/main/java/me/lucko/bytebin/content/storage/S3Backend.java b/src/main/java/me/lucko/bytebin/content/storage/S3Backend.java
index 2251dbb..2d07f65 100644
--- a/src/main/java/me/lucko/bytebin/content/storage/S3Backend.java
+++ b/src/main/java/me/lucko/bytebin/content/storage/S3Backend.java
@@ -33,6 +33,7 @@
 import software.amazon.awssdk.core.ResponseInputStream;
 import software.amazon.awssdk.core.sync.RequestBody;
 import software.amazon.awssdk.services.s3.S3Client;
+import software.amazon.awssdk.services.s3.S3ClientBuilder;
 import software.amazon.awssdk.services.s3.model.DeleteObjectRequest;
 import software.amazon.awssdk.services.s3.model.GetObjectRequest;
 import software.amazon.awssdk.services.s3.model.GetObjectResponse;
@@ -44,6 +45,7 @@
 import software.amazon.awssdk.services.s3.model.S3Object;
 import software.amazon.awssdk.services.s3.paginators.ListObjectsV2Iterable;
 
+import java.net.URI;
 import java.util.Date;
 import java.util.HashMap;
 import java.util.Map;
@@ -68,7 +70,14 @@ public S3Backend(String backendId, String bucketName) {
         this.bucketName = bucketName;
 
         // configure with environment variables: AWS_REGION, AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY
-        this.client = S3Client.builder().build();
+        S3ClientBuilder builder = S3Client.builder();
+
+        String s3EndpointUrl = System.getenv("AWS_S3_ENDPOINT_URL");
+        if (s3EndpointUrl != null && !s3EndpointUrl.isBlank()) {
+            builder = builder.endpointOverride(URI.create(s3EndpointUrl));
+        }
+
+        this.client = builder.build();
     }
 
     @Override