--- a/src/Makefile	2020-05-14 22:01:09.565870733 +0200
+++ b/src/Makefile	2020-05-14 22:06:49.081621996 +0200
@@ -18,6 +18,7 @@
 
 include $(CONFIG)
 #GTKCFLAGS += -Werror -Wno-error=deprecated-declarations
+CFLAGS=
 
 TARGETS = varcc$(XE) lablgtktop$(XE) lablgtk2$(XB) gdk_pixbuf_mlsource$(XE) \
 	$(THINITOBJS) build.ml
@@ -44,15 +45,13 @@
 endif
 
 ifdef DEBUG
-COMPILER += -warn-error A-52
-CFLAGS = -g $(GTKCFLAGS)
+OCAMLCFLAGS = $(GTKCFLAGS)
 CUSTOM = -custom
 #MLLINK += -cclib -lcamlrund
 MLBYTEFLAGS = -g -dtypes
 else
-CFLAGS = -DG_DISABLE_ASSERT -DG_DISABLE_CAST_CHECKS $(GTKCFLAGS)
+OCAMLCFLAGS = -DG_DISABLE_ASSERT -DG_DISABLE_CAST_CHECKS $(GTKCFLAGS)
 ifneq ($(TOOLCHAIN),msvc)
-CFLAGS += -O
 endif
 endif
 
@@ -65,9 +65,9 @@
 THLINK = unix.cma threads.cma
 
 ifdef USE_CC
-CCOMPILER = $(CC) -c -I"$(LIBDIR)" $(CFLAGS)
+CCOMPILER = $(CC) -c -I"$(LIBDIR)" $(OCAMLCFLAGS) $(CFLAGS)
 else
-CCOMPILER = $(CAMLC) -c -ccopt '$(CFLAGS)' -verbose
+CCOMPILER = $(CAMLC) -c -ccopt '$(OCAMLCFLAGS) $(CFLAGS)' -verbose
 endif
 
 ifdef USE_GL
@@ -123,7 +123,7 @@
 CLIBS += liblablrsvg$(XA)
 RSVGMLOBJS = rsvg.cmo
 RSVGCOBJS = ml_rsvg$(XO)
-$(RSVGCOBJS) : CFLAGS+=$(HAVE_SVGZ)
+$(RSVGCOBJS) : OCAMLCFLAGS+=$(HAVE_SVGZ)
 endif
 
 ifdef USE_GTKSPELL
@@ -140,7 +140,7 @@
 opt::  lablgtksourceview.cmxs
 endif
 
-ml_gtksourceview.o: CFLAGS=$(GTKSOURCEVIEWCFLAGS)
+ml_gtksourceview.o: OCAMLCFLAGS=$(GTKSOURCEVIEWCFLAGS)
 GTKSOURCEVIEWMLOBJS = gtkSourceView.cmo gSourceView.cmo
 GTKSOURCEVIEWCOBJS = ml_gtksourceview$(XO)
 ml_gtksourceview.c: pango_tags.h
@@ -179,7 +179,7 @@
 endif
 
 ifdef USE_GTKQUARTZ
-CFLAGS += -DHAS_GTKQUARTZ
+OCAMLCFLAGS += -DHAS_GTKQUARTZ
 endif
 # Rules
 .SUFFIXES: .ml .mli .cmo .cmi .cmx .cmxs .cmxa .c $(XO) .d$(XO) .var .h .opt .def .ml4
@@ -188,7 +188,7 @@
 .cpp$(XO):
 	$(CCOMPILER) $<
 .c.d$(XO):
-	$(CAMLC) -c -ccopt '-MT -DCAML_DLL -Fo$@ $(CFLAGS)' $<
+	$(CAMLC) -c -ccopt '-MT -DCAML_DLL -Fo$@ $(OCAMLCFLAGS) $(CFLAGS)' $<
 .ml.cmo:
 	$(COMPILER) $(PRINCIPAL) $<
 .mli.cmi:
--- a/src/ml_gdk.h	2020-05-14 22:19:59.045394874 +0200
+++ b/src/ml_gdk.h	2020-05-14 22:20:06.694277819 +0200
@@ -102,7 +102,7 @@
 CAMLexport int OptFlags_GdkModifier_val (value);
 CAMLexport int Flags_GdkModifier_val (value);
 CAMLexport int Flags_Event_mask_val (value);
-CAMLexport lookup_info *ml_table_extension_events;
+extern lookup_info *ml_table_extension_events;
 #define Extension_events_val(key) ml_lookup_to_c(ml_table_extension_events,key)
 
 #define GdkDragContext_val(val) check_cast(GDK_DRAG_CONTEXT,val)
--- a/src/ml_gdk.c	2020-05-14 22:21:39.244861128 +0200
+++ b/src/ml_gdk.c	2020-05-14 22:21:57.571580518 +0200
@@ -55,6 +55,8 @@
 #define GDK_WINDOW_TYPE_HINT_DOCK GDK_WINDOW_TYPE_HINT_NORMAL
 #endif
 
+lookup_info *ml_table_extension_events;
+
 CAMLprim void ml_raise_gdk (const char *errmsg)
 {
   static const value * exn = NULL;