diff --git a/pgpainless-core/src/test/kotlin/org/pgpainless/bouncycastle/extensions/PGPKeyRingExtensionsTest.kt b/pgpainless-core/src/test/kotlin/org/pgpainless/bouncycastle/extensions/PGPKeyRingExtensionsTest.kt
new file mode 100644
index 00000000..8ff941ba
--- /dev/null
+++ b/pgpainless-core/src/test/kotlin/org/pgpainless/bouncycastle/extensions/PGPKeyRingExtensionsTest.kt
@@ -0,0 +1,72 @@
+// SPDX-FileCopyrightText: 2024 Paul Schaub <vanitasvitae@fsfe.org>
+//
+// SPDX-License-Identifier: Apache-2.0
+
+package org.pgpainless.bouncycastle.extensions
+
+import org.junit.jupiter.api.Assertions.assertDoesNotThrow
+import org.junit.jupiter.api.Assertions.assertFalse
+import org.junit.jupiter.api.Assertions.assertNotNull
+import org.junit.jupiter.api.Assertions.assertTrue
+import org.junit.jupiter.api.Test
+import org.junit.jupiter.api.assertThrows
+import org.pgpainless.key.TestKeys
+
+class PGPKeyRingExtensionsTest {
+
+    @Test
+    fun `public key ring has public key`() {
+        val key = TestKeys.getJulietPublicKeyRing()
+        assertTrue(key.hasPublicKey(TestKeys.JULIET_KEY_ID))
+        assertTrue(key.hasPublicKey(TestKeys.JULIET_FINGERPRINT))
+
+        assertFalse(key.hasPublicKey(TestKeys.ROMEO_KEY_ID))
+        assertFalse(key.hasPublicKey(TestKeys.ROMEO_FINGERPRINT))
+    }
+
+    @Test
+    fun `secret key ring has public key`() {
+        val key = TestKeys.getJulietSecretKeyRing()
+        assertTrue(key.hasPublicKey(TestKeys.JULIET_KEY_ID))
+        assertTrue(key.hasPublicKey(TestKeys.JULIET_FINGERPRINT))
+
+        assertFalse(key.hasPublicKey(TestKeys.ROMEO_KEY_ID))
+        assertFalse(key.hasPublicKey(TestKeys.ROMEO_FINGERPRINT))
+    }
+
+    @Test
+    fun `test requirePublicKey on secret key ring`() {
+        val key = TestKeys.getJulietSecretKeyRing()
+        assertNotNull(assertDoesNotThrow {
+            key.requirePublicKey(TestKeys.JULIET_KEY_ID)
+        })
+        assertNotNull(assertDoesNotThrow {
+            key.requirePublicKey(TestKeys.JULIET_FINGERPRINT)
+        })
+
+        assertThrows<NoSuchElementException> {
+            key.requirePublicKey(TestKeys.ROMEO_KEY_ID)
+        }
+        assertThrows<NoSuchElementException> {
+            key.requirePublicKey(TestKeys.ROMEO_FINGERPRINT)
+        }
+    }
+
+    @Test
+    fun `test requirePublicKey on public key ring`() {
+        val key = TestKeys.getJulietPublicKeyRing()
+        assertNotNull(assertDoesNotThrow {
+            key.requirePublicKey(TestKeys.JULIET_KEY_ID)
+        })
+        assertNotNull(assertDoesNotThrow {
+            key.requirePublicKey(TestKeys.JULIET_FINGERPRINT)
+        })
+
+        assertThrows<NoSuchElementException> {
+            key.requirePublicKey(TestKeys.ROMEO_KEY_ID)
+        }
+        assertThrows<NoSuchElementException> {
+            key.requirePublicKey(TestKeys.ROMEO_FINGERPRINT)
+        }
+    }
+}