diff --git a/fluid/Makefile b/fluid/Makefile
index 6c1469581..2823e5f4d 100644
--- a/fluid/Makefile
+++ b/fluid/Makefile
@@ -1,7 +1,7 @@
 #
-# FLUID makefile for the Fast Light Tool Kit (FLTK).
+# FLUID Makefile for the Fast Light Tool Kit (FLTK).
 #
-# Copyright 1998-2017 by Bill Spitzak and others.
+# Copyright 1998-2020 by Bill Spitzak and others.
 #
 # This library is free software. Distribution and use rights are outlined in
 # the file "COPYING" which should have been included with this file.  If this
@@ -120,16 +120,16 @@ uninstall-linux:
 uninstall-osx:
 	$(RM) -r $(DESTDIR)/Applications/fluid.app
 
-
-#
 # Note: The rebuild target can only be used if you have the original .fl
-#       files.  This is normally only used by the FLTK maintainers...
-#
+#	files. This is normally only used by the FLTK maintainers...
+#	It *must* be executed *after* fluid has been built and
+#	fluid must be rebuilt if any {.fl|.cxx|.h} files were changed.
 
-rebuild:
-	./fluid -u -c about_panel.fl
-	./fluid -u -c alignment_panel.fl
-	./fluid -u -c function_panel.fl
-	./fluid -u -c print_panel.fl
-	./fluid -u -c template_panel.fl
-	./fluid -u -c widget_panel.fl
+rebuild: fluid$(EXEEXT)
+	echo 'Rebuilding fluid (.fl) and .cxx/.h files from .fl files ...'
+	./fluid$(EXEEXT) -u -c about_panel.fl
+	./fluid$(EXEEXT) -u -c alignment_panel.fl
+	./fluid$(EXEEXT) -u -c function_panel.fl
+	./fluid$(EXEEXT) -u -c print_panel.fl
+	./fluid$(EXEEXT) -u -c template_panel.fl
+	./fluid$(EXEEXT) -u -c widget_panel.fl
diff --git a/fluid/fluid.cxx b/fluid/fluid.cxx
index dcea17e7c..1f7e27790 100644
--- a/fluid/fluid.cxx
+++ b/fluid/fluid.cxx
@@ -1750,7 +1750,9 @@ static void sigint(SIGARG) {
 int main(int argc,char **argv) {
   int i = 1;
 
-  setlocale(LC_ALL, "");    // enable multilanguage errors in file chooser
+  setlocale(LC_ALL, "");      // enable multilanguage errors in file chooser
+  setlocale(LC_NUMERIC, "C"); // make sure numeric values are written correctly
+
   if (!Fl::args(argc,argv,i,arg) || i < argc-1) {
     static const char *msg =
       "usage: %s <switches> name.fl\n"
diff --git a/src/Makefile b/src/Makefile
index c1409a59a..c2577c0d7 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -582,6 +582,16 @@ mgwfltknox_images-$(FL_DSO_VERSION).dll: $(IMGLIBNAME) mgwfltknox-$(FL_DSO_VERSI
 		-L. -lfltk -Wl,--exclude-libs -Wl,libfltk_png.a \
 			$(IMAGELIBS) $(LDLIBS)
 
+# Note: The rebuild target can only be used if you have the original .fl
+#	files. This is normally only used by the FLTK maintainers...
+#	It *must* be executed *after* fluid has been built and
+#	the libs must be rebuilt if any {.fl|.cxx|.h} files were changed.
+
+rebuild:
+	echo 'Rebuilding fluid (.fl) and .cxx/.h files from .fl files ...'
+	../fluid/fluid$(EXEEXT) -u -c Fl_File_Chooser.fl
+	../fluid/fluid$(EXEEXT) -u -c Fl_Help_Dialog.fl
+
 clean:
 	-$(RM)	*.o xutf8/*.o *.dll.a core.* *~ *.bak *.bck
 	-$(RM)	drivers/Cocoa/*.o