--- src/npw-viewer.sh
+++ src/npw-viewer.sh
@@ -5,6 +5,11 @@
 OS="`uname -s | tr '[A-Z]' '[a-z]'`"
 ARCH="`uname -m`"
 
+# Adobe Flash can be confised by by a recent GTK+ that may use custom
+# window structure instead of native X Window. Revert to the old dumb
+# behavior and use native X window for all objects. (bnc#537788)
+export GDK_NATIVE_WINDOWS=1
+
 if test -z "$TARGET_OS"; then
     echo "*** NSPlugin Viewer *** error, TARGET_OS not initialized"
     exit 1