diff --git a/client.cpp b/client.cpp
index a9a5f886a1..ba54483e65 100644
--- a/client.cpp
+++ b/client.cpp
@@ -744,7 +744,8 @@ void Client::setMask(const QRegion& reg, int mode)
     }
     if (shape()) {
         // The rest of the applyign using a temporary window
-        XRectangle rec = { 0, 0, clientSize().width(), clientSize().height() };
+        XRectangle rec = { 0, 0, static_cast<unsigned short>(clientSize().width()),
+                           static_cast<unsigned short>(clientSize().height()) };
         XShapeCombineRectangles(display(), shape_helper_window, ShapeBounding,
                                 clientPos().x(), clientPos().y(), &rec, 1, ShapeSubtract, Unsorted);
         XShapeCombineShape(display(), shape_helper_window, ShapeBounding,
diff --git a/lanczosfilter.cpp b/lanczosfilter.cpp
index 67277c6736..2d976a58f9 100644
--- a/lanczosfilter.cpp
+++ b/lanczosfilter.cpp
@@ -432,7 +432,8 @@ void LanczosFilter::prepareRenderStates(GLTexture* tex, double opacity, double b
         // Note that both operands have to be in range [0.5; 1] since opengl
         //  automatically substracts 0.5 from them
         glActiveTexture(GL_TEXTURE1);
-        float saturation_constant[] = { 0.5 + 0.5 * 0.30, 0.5 + 0.5 * 0.59, 0.5 + 0.5 * 0.11, saturation };
+        float saturation_constant[] = { 0.5 + 0.5 * 0.30, 0.5 + 0.5 * 0.59, 0.5 + 0.5 * 0.11,
+                                        static_cast<float>(saturation) };
         glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_COMBINE);
         glTexEnvi(GL_TEXTURE_ENV, GL_COMBINE_RGB, GL_DOT3_RGB);
         glTexEnvi(GL_TEXTURE_ENV, GL_SOURCE0_RGB, GL_PREVIOUS);
@@ -500,7 +501,8 @@ void LanczosFilter::prepareRenderStates(GLTexture* tex, double opacity, double b
                       opacity);
         } else {
             // Multiply color by brightness and replace alpha by opacity
-            float constant[] = { opacityByBrightness, opacityByBrightness, opacityByBrightness, opacity };
+            float constant[] = { opacityByBrightness, opacityByBrightness, opacityByBrightness,
+                                 static_cast<float>(opacity) };
             glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_COMBINE);
             glTexEnvi(GL_TEXTURE_ENV, GL_COMBINE_RGB, GL_MODULATE);
             glTexEnvi(GL_TEXTURE_ENV, GL_SOURCE0_RGB, GL_TEXTURE);
diff --git a/libkwineffects/kwingltexture.cpp b/libkwineffects/kwingltexture.cpp
index a3fbec9d02..f03d357acd 100644
--- a/libkwineffects/kwingltexture.cpp
+++ b/libkwineffects/kwingltexture.cpp
@@ -311,10 +311,10 @@ void GLTexture::render(QRegion region, const QRect& rect, bool hardwareClipping)
         }
         const float verts[ 4 * 2 ] = {
             // NOTICE: r.x/y could be replaced by "0", but that would make it unreadable...
-            r.x(), r.y(),
-            r.x(), r.y() + rect.height(),
-            r.x() + rect.width(), r.y(),
-            r.x() + rect.width(), r.y() + rect.height()
+            static_cast<float>(r.x()), static_cast<float>(r.y()),
+            static_cast<float>(r.x()), static_cast<float>(r.y() + rect.height()),
+            static_cast<float>(r.x() + rect.width()), static_cast<float>(r.y()),
+            static_cast<float>(r.x() + rect.width()), static_cast<float>(r.y() + rect.height())
         };
 #ifdef KWIN_HAVE_OPENGLES
         const float texWidth = 1.0f;
diff --git a/overlaywindow.cpp b/overlaywindow.cpp
index 528dade5df..221118e8da 100644
--- a/overlaywindow.cpp
+++ b/overlaywindow.cpp
@@ -142,7 +142,7 @@ void OverlayWindow::destroy()
     if (m_window == None)
         return;
     // reset the overlay shape
-    XRectangle rec = { 0, 0, displayWidth(), displayHeight() };
+    XRectangle rec = { 0, 0, static_cast<unsigned short>(displayWidth()), static_cast<unsigned short>(displayHeight()) };
     XShapeCombineRectangles(display(), m_window, ShapeBounding, 0, 0, &rec, 1, ShapeSet, Unsorted);
     XShapeCombineRectangles(display(), m_window, ShapeInput, 0, 0, &rec, 1, ShapeSet, Unsorted);
 #ifdef KWIN_HAVE_XCOMPOSITE_OVERLAY
diff --git a/scene_opengl.cpp b/scene_opengl.cpp
index 7f2368efff..81f1db521d 100644
--- a/scene_opengl.cpp
+++ b/scene_opengl.cpp
@@ -1299,7 +1299,8 @@ void SceneOpenGL1Window::prepareStates(TextureType type, qreal opacity, qreal br
         // Note that both operands have to be in range [0.5; 1] since opengl
         //  automatically substracts 0.5 from them
         glActiveTexture(GL_TEXTURE1);
-        float saturation_constant[] = { 0.5 + 0.5 * 0.30, 0.5 + 0.5 * 0.59, 0.5 + 0.5 * 0.11, saturation };
+        float saturation_constant[] = { 0.5 + 0.5 * 0.30, 0.5 + 0.5 * 0.59, 0.5 + 0.5 * 0.11,
+                                        static_cast<float>(saturation) };
         glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_COMBINE);
         glTexEnvi(GL_TEXTURE_ENV, GL_COMBINE_RGB, GL_DOT3_RGB);
         glTexEnvi(GL_TEXTURE_ENV, GL_SOURCE0_RGB, GL_PREVIOUS);
@@ -1367,7 +1368,8 @@ void SceneOpenGL1Window::prepareStates(TextureType type, qreal opacity, qreal br
                       opacity);
         } else {
             // Multiply color by brightness and replace alpha by opacity
-            float constant[] = { opacityByBrightness, opacityByBrightness, opacityByBrightness, opacity };
+            float constant[] = { opacityByBrightness, opacityByBrightness, opacityByBrightness,
+                                 static_cast<float>(opacity) };
             glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_COMBINE);
             glTexEnvi(GL_TEXTURE_ENV, GL_COMBINE_RGB, GL_MODULATE);
             glTexEnvi(GL_TEXTURE_ENV, GL_SOURCE0_RGB, GL_TEXTURE);
diff --git a/scene_xrender.cpp b/scene_xrender.cpp
index bc49e26e41..93d3502f49 100644
--- a/scene_xrender.cpp
+++ b/scene_xrender.cpp
@@ -696,7 +696,7 @@ XRenderComposite(display(), PictOpOver, _PART_->x11PictureHandle(), decorationAl
 
         if (data.brightness() < 1.0) {
             // fake brightness change by overlaying black
-            XRenderColor col = { 0, 0, 0, 0xffff *(1 - data.brightness()) * data.opacity() };
+            XRenderColor col = { 0, 0, 0, static_cast<unsigned short>(0xffff *(1 - data.brightness()) * data.opacity()) };
             if (blitInTempPixmap) {
                 XRenderFillRectangle(display(), PictOpOver, renderTarget, &col,
                                      -temp_visibleRect.left(), -temp_visibleRect.top(), width(), height());