diff --git a/activation.cpp b/activation.cpp
index 2330bdd933..e294ff4108 100644
--- a/activation.cpp
+++ b/activation.cpp
@@ -221,7 +221,7 @@ void Workspace::setActiveClient( Client* c, allowed_t )
     ++set_active_client_recursion;
     if( active_client != NULL )
         { // note that this may call setActiveClient( NULL ), therefore the recursion counter
-        active_client->setActive( false, !c || !c->isModal() );
+            active_client->setActive( false, !c || !c->isModal() || c != active_client->transientFor() );
     }
     active_client = c;
     Q_ASSERT( c == NULL || c->isActive());
@@ -779,6 +779,11 @@ void Client::setActive( bool act, bool updateOpacity_)
     workspace()->setActiveClient( act ? this : NULL, Allowed );
     
     if (updateOpacity_) updateOpacity();
+    if (isModal() && transientFor())
+    {
+        if (!act) transientFor()->updateOpacity();
+        else if (!transientFor()->custom_opacity) transientFor()->setOpacity(options->translucentActiveWindows, options->activeWindowOpacity);
+    }
     updateShadowSize();
     
     if ( active )