diff --git a/pg/src/test/java/org/bouncycastle/openpgp/test/RegressionTest.java b/pg/src/test/java/org/bouncycastle/openpgp/test/RegressionTest.java
index 6c5ea8dd24..1c199a6ecf 100644
--- a/pg/src/test/java/org/bouncycastle/openpgp/test/RegressionTest.java
+++ b/pg/src/test/java/org/bouncycastle/openpgp/test/RegressionTest.java
@@ -76,7 +76,8 @@ public class RegressionTest
 
         new Curve25519PrivateKeyEncodingTest(),
         new EdDSAKeyConversionWithLeadingZeroTest(),
-        new ECDSAKeyPairTest()
+        new ECDSAKeyPairTest(),
+        new UnknownBCPGKeyPairTest()
     };
 
     public static void main(String[] args)
diff --git a/pg/src/test/java/org/bouncycastle/openpgp/test/UnknownBCPGKeyPairTest.java b/pg/src/test/java/org/bouncycastle/openpgp/test/UnknownBCPGKeyPairTest.java
new file mode 100644
index 0000000000..f347b1dbea
--- /dev/null
+++ b/pg/src/test/java/org/bouncycastle/openpgp/test/UnknownBCPGKeyPairTest.java
@@ -0,0 +1,45 @@
+package org.bouncycastle.openpgp.test;
+
+import org.bouncycastle.bcpg.PublicKeyPacket;
+import org.bouncycastle.bcpg.PublicSubkeyPacket;
+import org.bouncycastle.bcpg.UnknownBCPGKey;
+import org.bouncycastle.openpgp.PGPException;
+import org.bouncycastle.openpgp.PGPPublicKey;
+import org.bouncycastle.openpgp.operator.bc.BcKeyFingerprintCalculator;
+import org.bouncycastle.util.encoders.Hex;
+
+public class UnknownBCPGKeyPairTest
+        extends AbstractPgpKeyPairTest
+{
+    @Override
+    public String getName()
+    {
+        return "UnknownBCPGKeyPairTest";
+    }
+
+    @Override
+    public void performTest()
+            throws Exception
+    {
+        testGetBitStrength();
+    }
+
+    private void testGetBitStrength()
+            throws PGPException
+    {
+        byte[] raw = Hex.decode("decaffc0ffeebabe"); // 8 octets = 64-bit key size
+        UnknownBCPGKey key = new UnknownBCPGKey(raw.length, raw);
+        PublicKeyPacket packet = new PublicSubkeyPacket(
+                PublicKeyPacket.VERSION_6,
+                99, // unknown algorithm ID
+                currentTimeRounded(),
+                key);
+        PGPPublicKey pgpKey = new PGPPublicKey(packet, new BcKeyFingerprintCalculator());
+        isEquals("Unknown key getBitStrength() mismatch", 64, pgpKey.getBitStrength());
+    }
+
+    public static void main(String[] args)
+    {
+        runTest(new UnknownBCPGKeyPairTest());
+    }
+}