diff --git a/src/plot/Makefile.in b/src/plot/Makefile.in
index 581b9799bf..e0350a7adb 100644
--- a/src/plot/Makefile.in
+++ b/src/plot/Makefile.in
@@ -16,8 +16,8 @@ CC = @CC@
 #   seems like a good idea, but it doesn't work with
 #  libtool as the compiler. So, we trust the configuration
 #  that is built into dynext, instead.
-# WITH-ENV = env CC="$(CC)" LD="@MZLINKER@"
-WITH_ENV =
+# WITH-ENV = env CC="$(CC)" LD="@MZLINKER@" ...
+WITH_ENV = env CFLAGS="@CFLAGS@ @COMPFLAGS@ @PREFLAGS@" LDFLAGS="@LDFLAGS@"
 
 PLPLOT_SRCS = $(srcdir)/plplot/dc_drv.c \
               $(srcdir)/plplot/plcont.c \