diff --git a/effects/backgroundcontrast/contrast.cpp b/effects/backgroundcontrast/contrast.cpp
index a56b5f759c..3ef1cf1e0d 100644
--- a/effects/backgroundcontrast/contrast.cpp
+++ b/effects/backgroundcontrast/contrast.cpp
@@ -67,8 +67,9 @@ ContrastEffect::ContrastEffect()
     );
 
     // Fetch the contrast regions for all windows
-    foreach (EffectWindow *window, effects->stackingOrder())
+    for (EffectWindow *window: effects->stackingOrder()) {
         updateContrastRegion(window);
+    }
 }
 
 ContrastEffect::~ContrastEffect()
@@ -78,7 +79,14 @@ ContrastEffect::~ContrastEffect()
 
 void ContrastEffect::slotScreenGeometryChanged()
 {
-    effects->reloadEffect(this);
+    effects->makeOpenGLContextCurrent();
+    if (!supported()) {
+        effects->reloadEffect(this);
+        return;
+    }
+    for (EffectWindow *window: effects->stackingOrder()) {
+        updateContrastRegion(window);
+    }
 }
 
 void ContrastEffect::reconfigure(ReconfigureFlags flags)
diff --git a/effects/blur/blur.cpp b/effects/blur/blur.cpp
index 5f031d4a4f..b4a4d0139a 100644
--- a/effects/blur/blur.cpp
+++ b/effects/blur/blur.cpp
@@ -46,14 +46,7 @@ BlurEffect::BlurEffect()
         qCDebug(KWINEFFECTS) << "Simple blur shader failed to load";
     }
 
-    // Offscreen texture that's used as the target for the horizontal blur pass
-    // and the source for the vertical pass.
-    tex = GLTexture(GL_RGBA8, effects->virtualScreenSize());
-    tex.setFilter(GL_LINEAR);
-    tex.setWrapMode(GL_CLAMP_TO_EDGE);
-
-    target = new GLRenderTarget(tex);
-
+    updateTexture();
     reconfigure(ReconfigureAll);
 
     // ### Hackish way to announce support.
@@ -97,7 +90,23 @@ BlurEffect::~BlurEffect()
 
 void BlurEffect::slotScreenGeometryChanged()
 {
-    effects->reloadEffect(this);
+    effects->makeOpenGLContextCurrent();
+    updateTexture();
+    // Fetch the blur regions for all windows
+    foreach (EffectWindow *window, effects->stackingOrder())
+        updateBlurRegion(window);
+    effects->doneOpenGLContextCurrent();
+}
+
+void BlurEffect::updateTexture() {
+    delete target;
+    // Offscreen texture that's used as the target for the horizontal blur pass
+    // and the source for the vertical pass.
+    tex = GLTexture(GL_RGBA8, effects->virtualScreenSize());
+    tex.setFilter(GL_LINEAR);
+    tex.setWrapMode(GL_CLAMP_TO_EDGE);
+
+    target = new GLRenderTarget(tex);
 }
 
 void BlurEffect::reconfigure(ReconfigureFlags flags)
diff --git a/effects/blur/blur.h b/effects/blur/blur.h
index e6f44946db..85a7b4ae61 100644
--- a/effects/blur/blur.h
+++ b/effects/blur/blur.h
@@ -76,6 +76,7 @@ public Q_SLOTS:
     void slotScreenGeometryChanged();
 
 private:
+    void updateTexture();
     QRect expand(const QRect &rect) const;
     QRegion expand(const QRegion &region) const;
     QRegion blurRegion(const EffectWindow *w) const;
@@ -90,7 +91,7 @@ private:
 private:
     BlurShader *shader;
     GLShader *m_simpleShader;
-    GLRenderTarget *target;
+    GLRenderTarget *target = nullptr;
     GLTexture tex;
     long net_wm_blur_region;
     QRegion m_damagedArea; // keeps track of the area which has been damaged (from bottom to top)