diff --git a/clients/aurorae/src/qml/aurorae.qml b/clients/aurorae/src/qml/aurorae.qml
index 98deb9e4ce..25ef2eb1f3 100644
--- a/clients/aurorae/src/qml/aurorae.qml
+++ b/clients/aurorae/src/qml/aurorae.qml
@@ -151,6 +151,7 @@ Decoration {
     Text {
         id: caption
         text: decoration.caption
+        textFormat: Text.PlainText
         horizontalAlignment: auroraeTheme.horizontalAlignment
         verticalAlignment: auroraeTheme.verticalAlignment
         elide: Text.ElideRight
diff --git a/killer/killer.cpp b/killer/killer.cpp
index d37a654404..c88a9244f3 100644
--- a/killer/killer.cpp
+++ b/killer/killer.cpp
@@ -32,6 +32,8 @@ DEALINGS IN THE SOFTWARE.
 #include <X11/Xlib.h>
 #include <QX11Info>
 #include <QProcess>
+// TODO: remove with Qt 5, only for HTML escaping the caption
+#include <QTextDocument>
 #include <signal.h>
 #include <errno.h>
 
@@ -66,6 +68,9 @@ int main(int argc, char* argv[])
         KCmdLineArgs::usageError(i18n("This helper utility is not supposed to be called directly."));
         return 1;
     }
+    if (Qt::mightBeRichText(caption)) {
+        caption = Qt::escape(caption);
+    }
     QString question = i18n(
                            "<p>The window \"<b>%2</b>\" is not responding. "
                            "It belongs to the application <b>%1</b> (Process ID = %3, hostname = %4).</p>"