diff --git a/effects.h b/effects.h
--- a/effects.h
+++ b/effects.h
@@ -476,6 +476,7 @@
     QByteArray readProperty(long atom, long type, int format) const override;
     void deleteProperty(long atom) const override;
 
+    EffectWindow* transientFor() override;
     EffectWindow* findModal() override;
     EffectWindowList mainWindows() const override;
 
diff --git a/effects.cpp b/effects.cpp
--- a/effects.cpp
+++ b/effects.cpp
@@ -2002,6 +2002,21 @@
     return nullptr;
 }
 
+EffectWindow* EffectWindowImpl::transientFor()
+{
+    auto client = qobject_cast<AbstractClient *>(toplevel);
+    if (!client) {
+        return nullptr;
+    }
+
+    AbstractClient *transientFor = client->transientFor();
+    if (transientFor) {
+        return transientFor->effectWindow();
+    }
+
+    return nullptr;
+}
+
 QWindow *EffectWindowImpl::internalWindow() const
 {
     auto client = qobject_cast<InternalClient *>(toplevel);
diff --git a/effects/blur/blur.cpp b/effects/blur/blur.cpp
--- a/effects/blur/blur.cpp
+++ b/effects/blur/blur.cpp
@@ -606,11 +606,14 @@
             shape = shape & region;
         }
 
+        EffectWindow* modal = w->transientFor();
+        const bool transientForIsDock = (modal ? modal->isDock() : false);
+
         if (!shape.isEmpty()) {
-            doBlur(shape, screen, data.opacity(), data.screenProjectionMatrix(), w->isDock(), w->geometry());
+            doBlur(shape, screen, data.opacity(), data.screenProjectionMatrix(),w->isDock() || transientForIsDock, w->geometry());
         }
     }
-
+        
     // Draw the window over the blurred area
     effects->drawWindow(w, mask, region, data);
 }
diff --git a/libkwineffects/kwineffects.h b/libkwineffects/kwineffects.h
--- a/libkwineffects/kwineffects.h
+++ b/libkwineffects/kwineffects.h
@@ -2374,6 +2374,7 @@
     virtual bool keepBelow() const = 0;
 
     virtual bool isModal() const = 0;
+    Q_SCRIPTABLE virtual KWin::EffectWindow* transientFor() = 0;
     Q_SCRIPTABLE virtual KWin::EffectWindow* findModal() = 0;
     Q_SCRIPTABLE virtual QList<KWin::EffectWindow*> mainWindows() const = 0;