diff --git a/.travis.yml b/.travis.yml
index 3101f457..0d2a73aa 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,4 +1,5 @@
 language: java
+dist: trusty
 
 jdk:
   - oraclejdk11
diff --git a/src/net/i2p/crypto/eddsa/EdDSAEngine.java b/src/net/i2p/crypto/eddsa/EdDSAEngine.java
index 1f0ba6dd..6b254102 100644
--- a/src/net/i2p/crypto/eddsa/EdDSAEngine.java
+++ b/src/net/i2p/crypto/eddsa/EdDSAEngine.java
@@ -29,7 +29,6 @@
 import net.i2p.crypto.eddsa.math.Curve;
 import net.i2p.crypto.eddsa.math.GroupElement;
 import net.i2p.crypto.eddsa.math.ScalarOps;
-import sun.security.x509.X509Key;
 
 /**
  * Signing and verification for EdDSA.
@@ -157,7 +156,7 @@ protected void engineInitVerify(PublicKey publicKey) throws InvalidKeyException
                 }
             } else if (!key.getParams().getHashAlgorithm().equals(digest.getAlgorithm()))
                 throw new InvalidKeyException("Key hash algorithm does not match chosen digest");
-        } else if (publicKey instanceof X509Key) {
+        } else if (publicKey.getFormat().equals("X.509")) {
             // X509Certificate will sometimes contain an X509Key rather than the EdDSAPublicKey itself; the contained
             // key is valid but needs to be instanced as an EdDSAPublicKey before it can be used.
             EdDSAPublicKey parsedPublicKey;