diff --git a/sop-java/src/main/kotlin/sop/exception/SOPGPException.kt b/sop-java/src/main/kotlin/sop/exception/SOPGPException.kt
index 862e1bd..9df1628 100644
--- a/sop-java/src/main/kotlin/sop/exception/SOPGPException.kt
+++ b/sop-java/src/main/kotlin/sop/exception/SOPGPException.kt
@@ -16,6 +16,22 @@ abstract class SOPGPException : RuntimeException {
 
     abstract fun getExitCode(): Int
 
+    /** An otherwise unspecified failure occurred */
+    class UnspecificFailure : SOPGPException {
+
+        constructor(message: String) : super(message)
+
+        constructor(message: String, e: Throwable) : super(message, e)
+
+        constructor(e: Throwable) : super(e)
+
+        override fun getExitCode(): Int = EXIT_CODE
+
+        companion object {
+            const val EXIT_CODE = 1
+        }
+    }
+
     /** No acceptable signatures found (sop verify, inline-verify). */
     class NoSignature : SOPGPException {
         @JvmOverloads
@@ -378,4 +394,23 @@ abstract class SOPGPException : RuntimeException {
             const val EXIT_CODE = 107
         }
     }
+
+    /**
+     * Key not certification-capable (e.g., expired, revoked, unacceptable usage flags) (sop
+     * certify-userid)
+     */
+    class KeyCannotCertify : SOPGPException {
+
+        constructor(message: String) : super(message)
+
+        constructor(message: String, e: Throwable) : super(message, e)
+
+        constructor(e: Throwable) : super(e)
+
+        override fun getExitCode(): Int = EXIT_CODE
+
+        companion object {
+            const val EXIT_CODE = 109
+        }
+    }
 }