diff --git a/vertx-auth-webauthn/src/main/java/io/vertx/ext/auth/webauthn/impl/attestation/tpm/PubArea.java b/vertx-auth-webauthn/src/main/java/io/vertx/ext/auth/webauthn/impl/attestation/tpm/PubArea.java
index 38fa142ab..51a0c1eed 100644
--- a/vertx-auth-webauthn/src/main/java/io/vertx/ext/auth/webauthn/impl/attestation/tpm/PubArea.java
+++ b/vertx-auth-webauthn/src/main/java/io/vertx/ext/auth/webauthn/impl/attestation/tpm/PubArea.java
@@ -59,7 +59,7 @@ public PubArea(Buffer pubBuffer) {
       scheme = pubBuffer.getUnsignedShort(pos);
       pos+=2;
       curveID = pubBuffer.getUnsignedShort(pos);
-      pos+=4;
+      pos+=2;
       kdf = pubBuffer.getUnsignedShort(pos);
       pos+=2;
     } else {