diff --git a/abstract_client.h b/abstract_client.h
--- a/abstract_client.h
+++ b/abstract_client.h
@@ -348,7 +348,7 @@
      * @see captionNormal
      * @see captionSuffix
      **/
-    QString caption(bool full = true) const;
+    QString caption() const;
     /**
      * @returns The caption as set by the AbstractClient without any suffix.
      * @see caption
diff --git a/abstract_client.cpp b/abstract_client.cpp
--- a/abstract_client.cpp
+++ b/abstract_client.cpp
@@ -1766,15 +1766,12 @@
     return workspace()->findAbstractClient(fetchNameInternalPredicate);
 }
 
-QString AbstractClient::caption(bool full) const
-{
-    QString cap = captionNormal();
-    if (full) {
-        cap += captionSuffix();
-        if (unresponsive()) {
-            cap += QLatin1String(" ");
-            cap += i18nc("Application is not responding, appended to window title", "(Not Responding)");
-        }
+QString AbstractClient::caption() const
+{
+    QString cap = captionNormal() + captionSuffix();
+    if (unresponsive()) {
+        cap += QLatin1String(" ");
+        cap += i18nc("Application is not responding, appended to window title", "(Not Responding)");
     }
     return cap;
 }
diff --git a/client.cpp b/client.cpp
--- a/client.cpp
+++ b/client.cpp
@@ -1180,7 +1180,7 @@
         QString hostname = clientMachine()->isLocal() ? QStringLiteral("localhost") : QString::fromUtf8(clientMachine()->hostName());
         QProcess::startDetached(QStringLiteral(KWIN_KILLER_BIN),
                                 QStringList() << QStringLiteral("--pid") << QString::number(unsigned(pid)) << QStringLiteral("--hostname") << hostname
-                                << QStringLiteral("--windowname") << caption(false /*full*/)
+                                << QStringLiteral("--windowname") << captionNormal()
                                 << QStringLiteral("--applicationname") << QString::fromUtf8(resourceClass())
                                 << QStringLiteral("--wid") << QString::number(window())
                                 << QStringLiteral("--timestamp") << QString::number(timestamp),
diff --git a/rules.cpp b/rules.cpp
--- a/rules.cpp
+++ b/rules.cpp
@@ -460,7 +460,7 @@
                          // QueuedConnection, because title may change before
                          // the client is ready (could segfault!)
                          static_cast<Qt::ConnectionType>(Qt::QueuedConnection|Qt::UniqueConnection));
-    if (!matchTitle(c->caption(false)))
+    if (!matchTitle(c->captionNormal()))
         return false;
     return true;
 }