diff --git a/bcsop/src/main/java/org/pgpainless/bouncycastle/sop/operation/AbstractBCOperation.java b/bcsop/src/main/java/org/pgpainless/bouncycastle/sop/operation/AbstractBCOperation.java
index 05f1896..68ad348 100644
--- a/bcsop/src/main/java/org/pgpainless/bouncycastle/sop/operation/AbstractBCOperation.java
+++ b/bcsop/src/main/java/org/pgpainless/bouncycastle/sop/operation/AbstractBCOperation.java
@@ -1,6 +1,7 @@
 package org.pgpainless.bouncycastle.sop.operation;
 
 import org.bouncycastle.openpgp.PGPSessionKey;
+import org.bouncycastle.openpgp.PGPSignatureException;
 import org.bouncycastle.openpgp.api.OpenPGPMessageInputStream;
 import org.bouncycastle.openpgp.api.OpenPGPSignature;
 import org.bouncycastle.openpgp.api.exception.MalformedPGPSignatureException;
@@ -39,9 +40,9 @@ public abstract class AbstractBCOperation
                     verifications.add(verification);
                 }
             }
-            catch (MalformedPGPSignatureException e)
+            catch (PGPSignatureException e)
             {
-                // ignore malformed sig
+                // ignore malformed, invalid sig
             }
         }
         return verifications;