diff --git a/NOTES_4_0 b/NOTES_4_0
index 39922504fd..f712426608 100644
--- a/NOTES_4_0
+++ b/NOTES_4_0
@@ -26,6 +26,8 @@ This document is for creating the 4.0 release notes. There are 3 parts:
 Comments
 ========
 
+- mention how to turn it on
+- refer to COMPOSITE_HOWTO?
 
 
 Video
diff --git a/compositingprefs.cpp b/compositingprefs.cpp
index eda110c91f..d94da8bdf3 100644
--- a/compositingprefs.cpp
+++ b/compositingprefs.cpp
@@ -44,6 +44,12 @@ CompositingPrefs::~CompositingPrefs()
     {
     }
 
+bool CompositingPrefs::enableCompositing() const
+    {
+    return false; // disabled by default, for the time being, until support becomes better
+    return mEnableCompositing;
+    }
+
 bool CompositingPrefs::compositingPossible()
     {
 #ifdef KWIN_HAVE_COMPOSITING
diff --git a/compositingprefs.h b/compositingprefs.h
index 27749ea147..b73a6a99cd 100644
--- a/compositingprefs.h
+++ b/compositingprefs.h
@@ -52,7 +52,7 @@ public:
 
     static bool compositingPossible();
     static QString compositingNotPossibleReason();
-    bool enableCompositing() const  { return mEnableCompositing; }
+    bool enableCompositing() const;
     bool enableVSync() const  { return mEnableVSync; }
     bool enableDirectRendering() const  { return mEnableDirectRendering; }
     bool strictBinding() const { return mStrictBinding; }