Index: Makefile.in
===================================================================
--- Makefile.in	(revision 3579)
+++ Makefile.in	(working copy)
@@ -5,8 +5,9 @@
 BINDIR=%BINDIR%
 LIBDIR=%LIBDIR%
 BASEDIR=%BASEDIR%
+VA_COPY=%VA_COPY%
 
-CFLAGS   = -Wmissing-prototypes -Wstrict-prototypes -Wunused -Wall -g -Wa,-W
+CFLAGS   = -Wmissing-prototypes -Wstrict-prototypes -Wunused -Wall -g -Wa,-W $(VA_COPY)
 CPPFLAGS = -I. -I$(shell pwd)/core -I$(shell pwd)/kernelenv/include \
 	   -I$(shell pwd)/netfilter/include
 
Index: configure
===================================================================
--- configure	(revision 3579)
+++ configure	(working copy)
@@ -38,8 +38,19 @@
 [ -n "$BINDIR" ] || BINDIR="$PREFIX"/bin/
 [ -n "$LIBDIR" ] || LIBDIR="$PREFIX"/lib/
 
-SUB='s@%GCOVFLAGS%@'$GCOVFLAGS'@;s@%TYPE%@'$TYPE'@;s@%VERSION%@'$VERSION'@;s@%GCOV%@'$GCOV'@;s@%CC%@'$CC'@;s@%LIBDIR%@'$LIBDIR'@;s@%BINDIR%@'$BINDIR'@;s@%BASEDIR%@'$BASEDIR'@'
+echo "
+#include <stdarg.h>
+int main(int argc, char **argv)
+{
+	va_list ap1, ap2;
+	va_copy(ap1, ap2);
+	exit(0);
+}" >.va_copy.c
+gcc .va_copy.c -o /dev/null 2>/dev/null && VA_COPY="-DHAVE_VA_COPY"
+rm .va_copy.c
 
+SUB='s@%GCOVFLAGS%@'$GCOVFLAGS'@;s@%TYPE%@'$TYPE'@;s@%VERSION%@'$VERSION'@;s@%GCOV%@'$GCOV'@;s@%CC%@'$CC'@;s@%LIBDIR%@'$LIBDIR'@;s@%BINDIR%@'$BINDIR'@;s@%BASEDIR%@'$BASEDIR'@;s@%VA_COPY%@'$VA_COPY'@'
+
 [ -d $KERNELDIR/net/$TYPE/netfilter ] ||
 	barf No netfilter directory found in $KERNELDIR