diff --git a/src/test/java/org/janelia/saalfeldlab/n5/s3/AmazonS3KeyValueAccessTest.java b/src/test/java/org/janelia/saalfeldlab/n5/s3/AmazonS3KeyValueAccessTest.java
index 0820aa9..90f977a 100644
--- a/src/test/java/org/janelia/saalfeldlab/n5/s3/AmazonS3KeyValueAccessTest.java
+++ b/src/test/java/org/janelia/saalfeldlab/n5/s3/AmazonS3KeyValueAccessTest.java
@@ -1,10 +1,13 @@
 package org.janelia.saalfeldlab.n5.s3;
 
+import static org.junit.Assume.assumeTrue;
+
 import org.janelia.saalfeldlab.n5.KeyValueAccess;
 import org.janelia.saalfeldlab.n5.N5URI;
 import org.janelia.saalfeldlab.n5.kva.AbstractKeyValueAccessTest;
 import org.janelia.saalfeldlab.n5.s3.mock.MockS3Factory;
 import org.junit.After;
+import org.junit.BeforeClass;
 import org.junit.Ignore;
 import org.junit.Test;
 import software.amazon.awssdk.core.client.config.ClientOverrideConfiguration;
@@ -16,7 +19,14 @@
 import java.util.ArrayList;
 
 public class AmazonS3KeyValueAccessTest extends AbstractKeyValueAccessTest {
-	
+
+	@BeforeClass
+	public static void before() {
+
+		MockS3Factory.getOrCreateS3();
+		assumeTrue("mock s3 server not running", MockS3Factory.isMinioServerRunning());
+	}
+
 	private ArrayList<AmazonS3KeyValueAccess> kvas;
 
 	@Override
diff --git a/src/test/java/org/janelia/saalfeldlab/n5/s3/N5AmazonS3MockTests.java b/src/test/java/org/janelia/saalfeldlab/n5/s3/N5AmazonS3MockTests.java
index 303136a..6ed6e1d 100644
--- a/src/test/java/org/janelia/saalfeldlab/n5/s3/N5AmazonS3MockTests.java
+++ b/src/test/java/org/janelia/saalfeldlab/n5/s3/N5AmazonS3MockTests.java
@@ -1,7 +1,9 @@
 package org.janelia.saalfeldlab.n5.s3;
 
-import org.janelia.saalfeldlab.n5.s3.mock.MockS3Factory;
+import static org.junit.Assume.assumeTrue;
 
+import org.janelia.saalfeldlab.n5.s3.mock.MockS3Factory;
+import org.junit.BeforeClass;
 import org.junit.Ignore;
 import org.junit.Test;
 
@@ -9,6 +11,13 @@
 
 public class N5AmazonS3MockTests extends N5AmazonS3Tests {
 
+	@BeforeClass
+	public static void before() {
+
+		MockS3Factory.getOrCreateS3();
+		assumeTrue("mock s3 server not running", MockS3Factory.isMinioServerRunning());
+	}
+
 	@Override
 	protected S3Client getS3() {
 
diff --git a/src/test/java/org/janelia/saalfeldlab/n5/s3/mock/MockS3Factory.java b/src/test/java/org/janelia/saalfeldlab/n5/s3/mock/MockS3Factory.java
index f01b4d0..d8dae06 100644
--- a/src/test/java/org/janelia/saalfeldlab/n5/s3/mock/MockS3Factory.java
+++ b/src/test/java/org/janelia/saalfeldlab/n5/s3/mock/MockS3Factory.java
@@ -71,9 +71,6 @@ public static void startMinioServer() throws Exception {
 			return;
 		}
 
-		// TODO if the server fails to start for some reason
-		// e.g. minio server not installed
-		// probably should not fail, but report "mock test skipped" or something
 		minioServerDirectory = createTmpServerDirectory();
 		ProcessBuilder processBuilder = new ProcessBuilder("minio", "server", ".");
 		processBuilder.directory(minioServerDirectory.toFile());
@@ -104,7 +101,7 @@ private static Path createTmpServerDirectory() throws IOException {
 		return tempDirectory;
 	}
 
-	private static boolean isMinioServerRunning() {
+	public static boolean isMinioServerRunning() {
 
 		try {
 			minioUri.toURL().openConnection().connect();