Index: configure.in
--- configure.in.orig
+++ configure.in
@@ -31,7 +31,7 @@ fi
 dnl Check for headers
 AC_HEADER_STDC()
 
-CFLAGS="-Wall -Wno-sign-compare @OGG_CFLAGS@ @VORBIS_CFLAGS@ @AVILIB_CFLAGS@ @DEBUG_CFLAGS@ @PROFILING_CFLAGS@"
-CXXFLAGS="-Wall -Wno-sign-compare @OGG_CFLAGS@ @VORBIS_CFLAGS@ @AVILIB_CFLAGS@ @DEBUG_CFLAGS@ @PROFILING_CFLAGS@"
+CFLAGS="-Wall -Wno-sign-compare @OGG_CFLAGS@ @VORBIS_CFLAGS@ @AVILIB_CFLAGS@ @DEBUG_CFLAGS@ @PROFILING_CFLAGS@ ${CFLAGS}"
+CXXFLAGS="-Wall -Wno-sign-compare @OGG_CFLAGS@ @VORBIS_CFLAGS@ @AVILIB_CFLAGS@ @DEBUG_CFLAGS@ @PROFILING_CFLAGS@ ${CXXFLAGS}"
 
 AC_OUTPUT(Makefile avilib/Makefile)
