diff --git a/smack-experimental/src/test/java/org/jivesoftware/smackx/message_fastening/MessageFasteningElementsTest.java b/smack-experimental/src/test/java/org/jivesoftware/smackx/message_fastening/MessageFasteningElementsTest.java
index 9764b0363..8228fccfb 100644
--- a/smack-experimental/src/test/java/org/jivesoftware/smackx/message_fastening/MessageFasteningElementsTest.java
+++ b/smack-experimental/src/test/java/org/jivesoftware/smackx/message_fastening/MessageFasteningElementsTest.java
@@ -57,7 +57,7 @@ public class MessageFasteningElementsTest {
      */
     @Test
     public void fasteningElementSerializationTest() {
-        String xml = "" +
+        String xml =
                 "<apply-to xmlns='urn:xmpp:fasten:0' id='origin-id-1'>" +
                 "    <i-like-this xmlns='urn:example:like'/>" +
                 "</apply-to>";
@@ -73,7 +73,7 @@ public class MessageFasteningElementsTest {
     @ParameterizedTest
     @EnumSource(SmackTestUtil.XmlPullParserKind.class)
     public void fasteningDeserializationTest(SmackTestUtil.XmlPullParserKind parserKind) throws XmlPullParserException, IOException, SmackParsingException {
-        String xml = "" +
+        String xml =
                 "<apply-to xmlns='urn:xmpp:fasten:0' id='origin-id-1'>" +
                 "    <i-like-this xmlns='urn:example:like'/>" +
                 "    <external name='custom' element-namespace='urn:example:custom'/>" +
@@ -102,7 +102,7 @@ public class MessageFasteningElementsTest {
 
     @Test
     public void fasteningDeserializationClearTest() throws XmlPullParserException, IOException, SmackParsingException {
-        String xml = "" +
+        String xml =
                 "<apply-to xmlns='urn:xmpp:fasten:0' id='origin-id-1' clear='true'>" +
                 "    <i-like-this xmlns='urn:example:like'/>" +
                 "</apply-to>";
@@ -114,7 +114,7 @@ public class MessageFasteningElementsTest {
 
     @Test
     public void fasteningElementWithExternalElementsTest() {
-        String xml = "" +
+        String xml =
                 "<apply-to xmlns='urn:xmpp:fasten:0' id='origin-id-2'>" +
                 "    <external name='body'/>" +
                 "    <external name='custom' element-namespace='urn:example:custom'/>" +
diff --git a/smack-openpgp/src/test/java/org/jivesoftware/smackx/ox/TestKeys.java b/smack-openpgp/src/test/java/org/jivesoftware/smackx/ox/TestKeys.java
index f7b756bce..d6c28bf23 100644
--- a/smack-openpgp/src/test/java/org/jivesoftware/smackx/ox/TestKeys.java
+++ b/smack-openpgp/src/test/java/org/jivesoftware/smackx/ox/TestKeys.java
@@ -43,7 +43,7 @@ public class TestKeys {
     /**
      * Public key of xmpp:juliet@capulet.lit.
      */
-    public static final String JULIET_PUB = "" +
+    public static final String JULIET_PUB =
             "-----BEGIN PGP PUBLIC KEY BLOCK-----\n" +
             "\n" +
             "mQENBFrxov4BCAChZwPrBxxIlwzpieR5T2pnaOZLWH0WqSON6rVjvfbJHWdDi3Th\n" +
@@ -66,7 +66,7 @@ public class TestKeys {
     /**
      * Private key of xmpp:juliet@capulet.lit.
      */
-    public static final String JULIET_PRIV = "" +
+    public static final String JULIET_PRIV =
             "-----BEGIN PGP PRIVATE KEY BLOCK-----\n" +
             "\n" +
             "lQOYBFrxov4BCAChZwPrBxxIlwzpieR5T2pnaOZLWH0WqSON6rVjvfbJHWdDi3Th\n" +
@@ -104,7 +104,7 @@ public class TestKeys {
     /**
      * Public key of xmpp:romeo@montague.lit.
      */
-    public static final String ROMEO_PUB = "" +
+    public static final String ROMEO_PUB =
             "-----BEGIN PGP PUBLIC KEY BLOCK-----\n" +
             "\n" +
             "mQENBFrxopkBCADiYg/+mEObXgxuMW6/LFKpEyaJK9pBMgutuxnYZ9PXWZmOhDIT\n" +
@@ -127,7 +127,7 @@ public class TestKeys {
     /**
      * Private key of xmpp:romeo@montague.lit.
      */
-    public static final String ROMEO_PRIV = "" +
+    public static final String ROMEO_PRIV =
             "-----BEGIN PGP PRIVATE KEY BLOCK-----\n" +
             "\n" +
             "lQOYBFrxopkBCADiYg/+mEObXgxuMW6/LFKpEyaJK9pBMgutuxnYZ9PXWZmOhDIT\n" +