diff --git a/src/Gui/View3DInventorViewer.cpp b/src/Gui/View3DInventorViewer.cpp
index 540966ba9..1ab5eec2d 100644
--- a/src/Gui/View3DInventorViewer.cpp
+++ b/src/Gui/View3DInventorViewer.cpp
@@ -1284,7 +1284,7 @@ void View3DInventorViewer::renderToFramebuffer(QGLFramebufferObject* fbo)
 
     const QColor col = this->backgroundColor();
     glViewport(0, 0, width, height);
-    glClearColor(col.redF(), col.greenF(), col.blueF(), 1.0f);
+    glClearColor(col.redF(), col.greenF(), col.blueF(), col.alphaF());
     glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 
     glDepthRange(0.1,1.0);