--- Makefile.OCaml.orig	2021-12-18 15:04:56 UTC
+++ Makefile.OCaml
@@ -34,7 +34,11 @@ ifeq ($(shell uname),NetBSD)
 else
 ifeq ($(shell uname),NetBSD)
   OSARCH=NetBSD
+else
+ifeq ($(shell uname),FreeBSD)
+  OSARCH=FreeBSD
 endif
+endif
 ifeq ($(shell uname),Linux)
   OSARCH=Linux
 endif
@@ -301,6 +305,11 @@ endif
 INCLFLAGS+=-I fsmonitor -I fsmonitor/linux
 endif
 
+ifeq ($(OSARCH),FreeBSD)
+-include fsmonitor/linux/Makefile src/fsmonitor/linux/Makefile
+INCLFLAGS+=-I fsmonitor -I fsmonitor/linux
+endif
+
 ifeq ($(OSARCH),solaris)
 -include fsmonitor/solaris/Makefile src/fsmonitor/solaris/Makefile
 INCLFLAGS+=-I fsmonitor -I fsmonitor/solaris
@@ -427,6 +436,10 @@ win32rc/unison.res.lib: win32rc/unison.res
 	-$(RM) $@
 	ocamllex $<
 
+compat%.cmi: compat%.mli
+	@echo "$(CAMLC): $< ---> $@"
+	$(CAMLC) $(CAMLFLAGS) $(COMPATCAMLFLAGS) -c $(CWD)/$<
+
 %.cmi : %.mli
 	@echo "$(CAMLC): $< ---> $@"
 	$(CAMLC) $(CAMLFLAGS) $(COMPATCAMLFLAGS) -c $(CWD)/$<
@@ -451,7 +464,7 @@ compat%.cmx: compat%.ml
 
 %.o %.obj: %.c
 	@echo "$(CAMLC): $< ---> $@"
-	$(CAMLC) $(CAMLFLAGS) -ccopt $(OUTPUT_SEL)$(CWD)/$@ -c $(CWD)/$<
+	$(CAMLC) $(CAMLFLAGS) -ccopt $(OUTPUT_SEL)$(CWD)/$@ -c $(CFLAGS) $(CWD)/$<
 
 $(NAME)$(EXEC_EXT): $(CAMLOBJS) $(COBJS)
 	@echo Linking $@