Index: apl/src/Makefile.am
===================================================================
--- apl.orig/src/Makefile.am
+++ apl/src/Makefile.am
@@ -33,11 +33,10 @@ host_os = @host_os@
 # common means common to the apl and libapl builds
 #
 common_CXXFLAGS = -Wall $(plot_CXXFLAGS) -I sql -I $(abs_top_srcdir) $(CXX_WERROR)
-common_CXXFLAGS += $(GTK_CFLAGS) $(GTK_LIBS)
 common_CXXFLAGS += $(PYTHON_CFLAGS)
 common_LDFLAGS  = -export-dynamic $(GTK_LDFLAGS)
 
-common_SOURCES  = $(plot_SOURCES)
+common_SOURCES  = Plot_xcb.cc
 common_SOURCES +=						../buildtag.hh
 common_SOURCES +=						../config.h
 common_SOURCES +=						APL_Float_as_class.hh
Index: apl/src/Quad_PLOT.cc
===================================================================
--- apl.orig/src/Quad_PLOT.cc
+++ apl/src/Quad_PLOT.cc
@@ -40,6 +40,7 @@
 #  define MISSING1 " libX11.so"
 #endif       // HAVE_LIBX11
 
+#undef apl_GTK3
 #if apl_GTK3                            // ======== GTK based ⎕PLOT ========
 
 # if defined( HAVE_LIBGTK_3 )
@@ -613,7 +614,7 @@ Quad_PLOT::setup_data_3D(const Value & B
           for Y (height):
 
            X               Y               Z
-           ↓               ↓              
+           ↓               ↓
           ┌───────────────┬───────────────┐
           │ X-coordinates │ Y-coordinates │
           └───────────────┴───────────────┘
Index: apl/src/Quad_PNG.cc
===================================================================
--- apl.orig/src/Quad_PNG.cc
+++ apl/src/Quad_PNG.cc
@@ -28,6 +28,7 @@
 Quad_PNG  Quad_PNG::_fun;
 Quad_PNG * Quad_PNG::fun = &Quad_PNG::_fun;
 
+#undef apl_GTK3
 #if defined( apl_GTK3     ) && \
     defined( HAVE_LIBGTK_3 ) && \
     defined( HAVE_LIBZ     ) && \