diff --git a/src/main/java/com/rultor/agents/twitter/Tweets.java b/src/main/java/com/rultor/agents/twitter/Tweets.java
index 10904c080b..82a5cbbb1a 100644
--- a/src/main/java/com/rultor/agents/twitter/Tweets.java
+++ b/src/main/java/com/rultor/agents/twitter/Tweets.java
@@ -33,6 +33,7 @@
 import com.jcabi.aspects.Tv;
 import com.jcabi.github.Github;
 import com.jcabi.github.Issue;
+import com.jcabi.github.Language;
 import com.jcabi.github.Repo;
 import com.jcabi.log.Logger;
 import com.jcabi.xml.XML;
@@ -107,6 +108,7 @@ public Iterable<Directive> process(final XML xml) throws IOException {
      * @return Tweet text
      * @throws IOException If fails
      */
+    @SuppressWarnings("PMD.InsufficientStringBufferDeclaration")
     private static String tweet(final Repo.Smart repo, final String tag)
         throws IOException {
         final StringBuilder text = new StringBuilder(2 * Tv.HUNDRED);
@@ -120,10 +122,13 @@ private static String tweet(final Repo.Smart repo, final String tag)
                 )
             );
         }
-        return text.append(", ").append(tag)
+        text.append(", ").append(tag)
             .append(" released https://github.com/")
-            .append(repo.coordinates())
-            .toString();
+            .append(repo.coordinates());
+        for (final Language lang : repo.languages()) {
+            text.append(String.format(" #%s", lang));
+        }
+        return text.toString();
     }
 
 }
diff --git a/src/test/java/com/rultor/agents/twitter/TweetsTest.java b/src/test/java/com/rultor/agents/twitter/TweetsTest.java
index 3a649e720f..2e8c44ecdb 100644
--- a/src/test/java/com/rultor/agents/twitter/TweetsTest.java
+++ b/src/test/java/com/rultor/agents/twitter/TweetsTest.java
@@ -29,11 +29,21 @@
  */
 package com.rultor.agents.twitter;
 
+import com.google.common.collect.Lists;
+import com.jcabi.github.Coordinates;
+import com.jcabi.github.Github;
 import com.jcabi.github.Issue;
+import com.jcabi.github.Issues;
+import com.jcabi.github.Language;
 import com.jcabi.github.Repo;
+import com.jcabi.github.Repos;
 import com.jcabi.github.mock.MkGithub;
 import com.rultor.spi.Agent;
 import com.rultor.spi.Talk;
+import java.io.IOException;
+import java.util.List;
+import javax.json.Json;
+import javax.json.JsonObject;
 import org.junit.Ignore;
 import org.junit.Test;
 import org.mockito.Matchers;
@@ -46,6 +56,10 @@
  * @author Yegor Bugayenko (yegor@tpc2.com)
  * @version $Id$
  * @since 1.30
+ * @todo #561 When all the puzzles from
+ *  https://github.com/jcabi/jcabi-github/issues/923 are implemented, remove
+ *  repo, issue, lang methods, and use MkGithub family in all the tests. Also
+ *  enable postsTweet method.
  */
 public final class TweetsTest {
 
@@ -60,6 +74,78 @@ public void postsTweet() throws Exception {
         final Issue issue = repo.issues().create("", "");
         final Twitter twitter = Mockito.mock(Twitter.class);
         final Agent agent = new Tweets(repo.github(), twitter);
+        final Talk talk = this.talk(repo, issue);
+        agent.execute(talk);
+        Mockito.verify(twitter).post(
+            Matchers.contains("test")
+        );
+    }
+
+    /**
+     * Tweets can post a tweet with language tags.
+     * @throws Exception In case of error.
+     */
+    @Test
+    public void postsTweetWithLanguages() throws Exception {
+        final Repo repo = this.repo();
+        final List<Language> langs = Lists.newArrayList(
+            this.lang("Java"), this.lang("Python")
+        );
+        Mockito.when(repo.languages()).thenReturn(langs);
+        final Twitter twitter = Mockito.mock(Twitter.class);
+        final Agent agent = new Tweets(repo.github(), twitter);
+        final Talk talk = this.talk(repo, this.issue(repo));
+        agent.execute(talk);
+        Mockito.verify(twitter).post(
+            Matchers.contains(
+                String.format("#%s #%s", langs.get(0), langs.get(1))
+            )
+        );
+    }
+
+    /**
+     * Create mock issue.
+     * @param repo Repo to use
+     * @return Mocked issue.
+     */
+    private Issue issue(final Repo repo) {
+        final Issues issues = Mockito.mock(Issues.class);
+        final Issue issue = Mockito.mock(Issue.class);
+        Mockito.when(issue.repo()).thenReturn(repo);
+        Mockito.when(issues.get(Mockito.anyInt())).thenReturn(issue);
+        Mockito.when(repo.issues()).thenReturn(issues);
+        return issue;
+    }
+
+    /**
+     * Create mock repo.
+     * @return Mocked repo
+     * @throws IOException In case of error
+     */
+    private Repo repo() throws IOException {
+        final Github github = Mockito.mock(Github.class);
+        final Repo repo = Mockito.mock(Repo.class);
+        final JsonObject rjson = Json.createObjectBuilder()
+            .add("description", "something").build();
+        Mockito.when(repo.json()).thenReturn(rjson);
+        Mockito.when(repo.github()).thenReturn(github);
+        final Repos repos = Mockito.mock(Repos.class);
+        Mockito.when(github.repos()).thenReturn(repos);
+        final Coordinates coords = new Coordinates.Simple("foo/bar");
+        Mockito.when(repo.coordinates()).thenReturn(coords);
+        Mockito.when(repos.get(Mockito.any(Coordinates.class)))
+            .thenReturn(repo);
+        return repo;
+    }
+
+    /**
+     * Creates a talk with repo and issue.
+     * @param repo Repo to use
+     * @param issue Issue to use
+     * @return Created Talk
+     * @throws IOException In case of error
+     */
+    private Talk talk(final Repo repo, final Issue issue) throws IOException {
         final Talk talk = new Talk.InFile();
         talk.modify(
             new Directives().xpath("/talk").add("wire")
@@ -73,10 +159,24 @@ public void postsTweet() throws Exception {
                 .add("type").set("release").up()
                 .add("args").add("arg").attr("name", "tag").set("1.7")
         );
-        agent.execute(talk);
-        Mockito.verify(twitter).post(
-            Matchers.contains("test")
-        );
+        return talk;
     }
 
+    /**
+     * Create mock language.
+     * @param name Name of the language
+     * @return Language created.
+     */
+    private Language lang(final String name) {
+        return new Language() {
+            @Override
+            public String name() {
+                return name;
+            }
+            @Override
+            public long bytes() {
+                return 0;
+            }
+        };
+    }
 }