diff --git a/pgpainless-core/src/test/java/org/pgpainless/key/modification/AddUserIdTest.java b/pgpainless-core/src/test/java/org/pgpainless/key/modification/AddUserIdTest.java
index a6d861a5..2aa4fe04 100644
--- a/pgpainless-core/src/test/java/org/pgpainless/key/modification/AddUserIdTest.java
+++ b/pgpainless-core/src/test/java/org/pgpainless/key/modification/AddUserIdTest.java
@@ -18,17 +18,21 @@ package org.pgpainless.key.modification;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 
+import java.io.IOException;
 import java.security.InvalidAlgorithmParameterException;
 import java.security.NoSuchAlgorithmException;
 import java.util.Iterator;
+import java.util.NoSuchElementException;
 
 import org.bouncycastle.openpgp.PGPException;
 import org.bouncycastle.openpgp.PGPSecretKeyRing;
 import org.junit.Test;
 import org.pgpainless.PGPainless;
+import org.pgpainless.key.TestKeys;
 import org.pgpainless.key.collection.PGPKeyRing;
 import org.pgpainless.key.protection.PasswordBasedSecretKeyRingProtector;
 import org.pgpainless.key.protection.SecretKeyRingProtector;
+import org.pgpainless.key.protection.UnprotectedKeysProtector;
 import org.pgpainless.util.Passphrase;
 
 public class AddUserIdTest {
@@ -52,8 +56,33 @@ public class AddUserIdTest {
         assertEquals("cheshirecat@wonderland.lit", userIds.next());
         assertFalse(userIds.hasNext());
 
-        // CHECKSTYLE:OFF
-        // System.out.println(KeyPrinter.toAsciiArmoredString(secretKeys));
-        // CHECKSTYLE:ON
+        secretKeys = PGPainless.modifyKeyRing(secretKeys)
+                .deleteUserId("cheshirecat@wonderland.lit", protector)
+                .done();
+
+        userIds = secretKeys.getPublicKey().getUserIDs();
+        assertEquals("alice@wonderland.lit", userIds.next());
+        assertFalse(userIds.hasNext());
+    }
+
+    @Test(expected = NoSuchElementException.class)
+    public void addUserId_NoSuchElementExceptionForMissingKey() throws IOException, PGPException {
+        PGPSecretKeyRing secretKeys = TestKeys.getCryptieSecretKeyRing();
+        PGPainless.modifyKeyRing(secretKeys)
+                .addUserId(0L, TestKeys.CRYPTIE_UID, new UnprotectedKeysProtector());
+    }
+
+    @Test(expected = NoSuchElementException.class)
+    public void deleteUserId_noSuchElementExceptionForMissingUserId() throws IOException, PGPException {
+        PGPSecretKeyRing secretKeys = TestKeys.getCryptieSecretKeyRing();
+        PGPainless.modifyKeyRing(secretKeys)
+                .deleteUserId("invalid@user.id", new UnprotectedKeysProtector());
+    }
+
+    @Test(expected = NoSuchElementException.class)
+    public void deleteUserId_noSuchElementExceptionForMissingKey() throws IOException, PGPException {
+        PGPSecretKeyRing secretKeys = TestKeys.getCryptieSecretKeyRing();
+        PGPainless.modifyKeyRing(secretKeys)
+                .deleteUserId(0L, TestKeys.CRYPTIE_UID, new UnprotectedKeysProtector());
     }
 }
diff --git a/pgpainless-core/src/test/java/org/pgpainless/key/modification/KeyRingEditorTest.java b/pgpainless-core/src/test/java/org/pgpainless/key/modification/KeyRingEditorTest.java
new file mode 100644
index 00000000..80339b56
--- /dev/null
+++ b/pgpainless-core/src/test/java/org/pgpainless/key/modification/KeyRingEditorTest.java
@@ -0,0 +1,26 @@
+/*
+ * Copyright 2020 Paul Schaub.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.pgpainless.key.modification;
+
+import org.junit.Test;
+
+public class KeyRingEditorTest {
+
+    @Test(expected = NullPointerException.class)
+    public void testConstructorThrowsNpeForNull() {
+        new KeyRingEditor(null);
+    }
+}