diff -r a29623b68ca2 -r 296eac3183bc tests/plover-gtk/Makefile.am
--- a/tests/plover-gtk/Makefile.am	Mon Jun 13 12:18:42 2016 +0100
+++ b/tests/plover-gtk/Makefile.am	Fri Jul 08 08:26:29 2016 +0100
@@ -3,11 +3,13 @@
 LDADD=../../plover-gtk/libplover-gtk.la ../../plover/libplover.la \
   $(PLOVER_GTK_LIBS)
 
+TEST_EXTENSIONS =
+
 if HAVE_CHECK_TOOLS
 
 TESTS = $(txt_tests) $(gui_tests:=.xvfb)
 TESTS_ENVIRONMENT = gtk_srcdir="$(top_srcdir)/plover-gtk"
-TEST_EXTENSIONS = .xvfb
+TEST_EXTENSIONS += .xvfb
 XVFB_LOG_COMPILER = $(top_srcdir)/tests/xvfb-run
 XVFB_LOG_FLAGS = --auto-servernum --auth-file .Xauthority