diff --git a/shadow.cpp b/shadow.cpp
--- a/shadow.cpp
+++ b/shadow.cpp
@@ -331,51 +331,37 @@
 
 bool Shadow::updateShadow()
 {
-    auto clear = [this] {
-        if (m_topLevel && m_topLevel->shadow()) {
-            auto w = m_topLevel->effectWindow();
-            // this also deletes the shadow
-            w->sceneWindow()->updateShadow(nullptr);
-            emit m_topLevel->shadowChanged();
-        }
-    };
-
     if (!m_topLevel) {
         return false;
     }
 
     if (m_decorationShadow) {
         if (AbstractClient *c = qobject_cast<AbstractClient*>(m_topLevel)) {
             if (c->decoration()) {
                 if (init(c->decoration())) {
-                    emit m_topLevel->shadowChanged();
                     return true;
                 }
             }
         }
-        clear();
         return false;
     }
 
     if (waylandServer()) {
         if (m_topLevel && m_topLevel->surface()) {
             if (const auto &s = m_topLevel->surface()->shadow()) {
                 if (init(s)) {
-                    emit m_topLevel->shadowChanged();
                     return true;
                 }
             }
         }
     }
 
     auto data = Shadow::readX11ShadowProperty(m_topLevel->window());
     if (data.isEmpty()) {
-        clear();
         return false;
     }
 
     init(data);
-    emit m_topLevel->shadowChanged();
 
     return true;
 }
diff --git a/toplevel.cpp b/toplevel.cpp
--- a/toplevel.cpp
+++ b/toplevel.cpp
@@ -336,7 +336,10 @@
     const QRect oldVisibleRect = visibleRect();
     if (hasShadow()) {
         dirtyRect = shadow()->shadowRegion().boundingRect();
-        effectWindow()->sceneWindow()->shadow()->updateShadow();
+        if (!effectWindow()->sceneWindow()->shadow()->updateShadow()) {
+            effectWindow()->sceneWindow()->updateShadow(nullptr);
+        }
+        emit shadowChanged();
     } else {
         Shadow::createShadow(this);
     }