diff --git a/include/kopper_interface.h b/include/kopper_interface.h
index 3db53e8d52c..261d1222ec8 100644
--- a/include/kopper_interface.h
+++ b/include/kopper_interface.h
@@ -61,7 +61,8 @@ struct __DRIkopperExtensionRec {
                                         const __DRIconfig *config,
                                         void *loaderPrivate,
                                         int pixmap);
-    int64_t (*swapBuffers)(__DRIdrawable *draw);
+    /* flags is a set of __DRI2_FLUSH_* flags */
+    int64_t (*swapBuffers)(__DRIdrawable *draw, uint32_t flush_flags);
     void (*setSwapInterval)(__DRIdrawable *drawable, int interval);
     int (*queryBufferAge)(__DRIdrawable *drawable);
 };
diff --git a/src/egl/drivers/dri2/platform_x11.c b/src/egl/drivers/dri2/platform_x11.c
index 1dc2c1fef7a..a362ccef52b 100644
--- a/src/egl/drivers/dri2/platform_x11.c
+++ b/src/egl/drivers/dri2/platform_x11.c
@@ -953,7 +953,12 @@ dri2_x11_swap_buffers(_EGLDisplay *disp, _EGLSurface *draw)
    struct dri2_egl_surface *dri2_surf = dri2_egl_surface(draw);
 
    if (dri2_dpy->kopper) {
-      dri2_dpy->kopper->swapBuffers(dri2_surf->dri_drawable);
+      /* From the EGL 1.4 spec (page 52):
+       *
+       *     "The contents of ancillary buffers are always undefined
+       *      after calling eglSwapBuffers."
+       */
+      dri2_dpy->kopper->swapBuffers(dri2_surf->dri_drawable, __DRI2_FLUSH_INVALIDATE_ANCILLARY);
       return EGL_TRUE;
    } else if (!dri2_dpy->flush) {
       /* aka the swrast path, which does the swap in the gallium driver. */
diff --git a/src/gallium/frontends/dri/kopper.c b/src/gallium/frontends/dri/kopper.c
index 9e805697515..12141d42a4e 100644
--- a/src/gallium/frontends/dri/kopper.c
+++ b/src/gallium/frontends/dri/kopper.c
@@ -840,7 +840,7 @@ kopper_create_drawable(struct dri_screen *screen, const struct gl_config *visual
 }
 
 static int64_t
-kopperSwapBuffers(__DRIdrawable *dPriv)
+kopperSwapBuffers(__DRIdrawable *dPriv, uint32_t flush_flags)
 {
    struct dri_drawable *drawable = dri_drawable(dPriv);
    struct dri_context *ctx = dri_get_current();
@@ -861,7 +861,7 @@ kopperSwapBuffers(__DRIdrawable *dPriv)
    drawable->texture_stamp = drawable->lastStamp - 1;
 
    dri_flush(opaque_dri_context(ctx), opaque_dri_drawable(drawable),
-             __DRI2_FLUSH_DRAWABLE | __DRI2_FLUSH_CONTEXT,
+             __DRI2_FLUSH_DRAWABLE | __DRI2_FLUSH_CONTEXT | flush_flags,
              __DRI2_THROTTLE_SWAPBUFFER);
 
    kopper_copy_to_front(ctx->st->pipe, drawable, ptex);
@@ -881,7 +881,7 @@ kopperSwapBuffers(__DRIdrawable *dPriv)
 static void
 kopper_swap_buffers(struct dri_drawable *drawable)
 {
-   kopperSwapBuffers(opaque_dri_drawable(drawable));
+   kopperSwapBuffers(opaque_dri_drawable(drawable), 0);
 }
 
 static __DRIdrawable *
diff --git a/src/glx/drisw_glx.c b/src/glx/drisw_glx.c
index 0e41f8560a9..b69eb7c84a1 100644
--- a/src/glx/drisw_glx.c
+++ b/src/glx/drisw_glx.c
@@ -752,7 +752,7 @@ driswSwapBuffers(__GLXDRIdrawable * pdraw,
    }
 
    if (psc->kopper)
-       return psc->kopper->swapBuffers (pdp->driDrawable);
+       return psc->kopper->swapBuffers (pdp->driDrawable, 0);
 
    psc->core->swapBuffers(pdp->driDrawable);