diff --git a/pgpainless-core/src/main/java/org/pgpainless/key/collection/PGPKeyRingCollection.java b/pgpainless-core/src/main/java/org/pgpainless/key/collection/PGPKeyRingCollection.java
index 76c578f9..0cc9fccd 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/key/collection/PGPKeyRingCollection.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/key/collection/PGPKeyRingCollection.java
@@ -15,6 +15,7 @@
  */
 package org.pgpainless.key.collection;
 
+import org.bouncycastle.bcpg.MarkerPacket;
 import org.bouncycastle.openpgp.PGPException;
 import org.bouncycastle.openpgp.PGPKeyRing;
 import org.bouncycastle.openpgp.PGPObjectFactory;
@@ -64,6 +65,10 @@ public class PGPKeyRingCollection {
         List<PGPPublicKeyRing> publicKeyRings = new ArrayList<>();
 
         while ((obj = pgpFact.nextObject()) != null) {
+            if (obj instanceof MarkerPacket) {
+                // Skip marker packets
+                continue;
+            }
             if (obj instanceof PGPSecretKeyRing) {
                 secretKeyRings.add((PGPSecretKeyRing) obj);
             } else if (obj instanceof PGPPublicKeyRing) {
diff --git a/pgpainless-sop/src/main/java/org/pgpainless/sop/SopKeyUtil.java b/pgpainless-sop/src/main/java/org/pgpainless/sop/SopKeyUtil.java
index 786e8a95..8fe5337a 100644
--- a/pgpainless-sop/src/main/java/org/pgpainless/sop/SopKeyUtil.java
+++ b/pgpainless-sop/src/main/java/org/pgpainless/sop/SopKeyUtil.java
@@ -48,7 +48,9 @@ public class SopKeyUtil {
         List<PGPPublicKeyRing> publicKeyRings = new ArrayList<>();
         for (File file : files) {
             try (FileInputStream in = new FileInputStream(file)) {
-                PGPPublicKeyRingCollection collection = PGPainless.readKeyRing().publicKeyRingCollection(in);
+                PGPPublicKeyRingCollection collection = PGPainless.readKeyRing()
+                        .keyRingCollection(in, true)
+                        .getPgpPublicKeyRingCollection();
                 for (PGPPublicKeyRing keyRing : collection) {
                     publicKeyRings.add(keyRing);
                 }