diff --git a/hw/xfree86/drivers/modesetting/driver.c b/hw/xfree86/drivers/modesetting/driver.c
index a8e83b291..f98d6da2b 100644
--- a/hw/xfree86/drivers/modesetting/driver.c
+++ b/hw/xfree86/drivers/modesetting/driver.c
@@ -586,13 +586,24 @@ dispatch_slave_dirty(ScreenPtr pScreen)
 static void
 redisplay_dirty(ScreenPtr screen, PixmapDirtyUpdatePtr dirty)
 {
-
+    modesettingPtr ms = modesettingPTR(xf86ScreenToScrn(screen));
     RegionRec pixregion;
 
     PixmapRegionInit(&pixregion, dirty->slave_dst);
     DamageRegionAppend(&dirty->slave_dst->drawable, &pixregion);
     PixmapSyncDirtyHelper(dirty);
 
+    if (!screen->isGPU) {
+        /*
+         * When copying from the master framebuffer to the shared pixmap,
+         * we must ensure the copy is complete before the slave starts a
+         * copy to its own framebuffer (some slaves scanout directly from
+         * the shared pixmap, but not all).
+         */
+        if (ms->drmmode.glamor)
+            glamor_finish(screen);
+    }
+
     DamageRegionProcessPending(&dirty->slave_dst->drawable);
     RegionUninit(&pixregion);
 }