diff --git a/src/test/java/io/vertx/test/core/TestUtils.java b/src/test/java/io/vertx/test/core/TestUtils.java
index e8b89d827cd..82b18c31b1d 100644
--- a/src/test/java/io/vertx/test/core/TestUtils.java
+++ b/src/test/java/io/vertx/test/core/TestUtils.java
@@ -31,9 +31,6 @@
 import java.util.stream.Collectors;
 import java.util.stream.StreamSupport;
 import java.util.zip.GZIPOutputStream;
-
-import javax.security.cert.X509Certificate;
-
 import io.netty.buffer.Unpooled;
 import io.netty.handler.codec.http2.Http2CodecUtil;
 import io.netty.util.NetUtil;
@@ -472,12 +469,6 @@ public static String cnOf(Certificate cert) throws Exception {
     return null;
   }
 
-  public static String cnOf(X509Certificate cert) throws Exception {
-    String dn = cert.getSubjectDN().getName();
-    List<String> names = KeyStoreHelper.getX509CertificateCommonNames(dn);
-    return names.isEmpty() ? null : names.get(0);
-  }
-
   /**
    * @return the loopback address for testing
    */