Copied from Debian.

Description: Explicitely link against -lm
Bug-Debian: http://bugs.debian.org/553595
Author: Fabian Greffrath <fabian@debian-unofficial.org>, Dmitrijs Ledkovs <dmitrij.ledkov@gmail.com>

---
 libao/Makefile.am |    1 +
 src/Makefile.am   |    2 +-
 2 files changed, 2 insertions(+), 1 deletions(-)

--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -1,9 +1,9 @@
-CFLAGS = @A52DEC_CFLAGS@
+AM_CFLAGS = @A52DEC_CFLAGS@
 
 bin_PROGRAMS = a52dec extract_a52
 a52dec_SOURCES = a52dec.c getopt.c gettimeofday.c
 a52dec_LDADD = $(top_builddir)/liba52/liba52.la \
-	       $(top_builddir)/libao/libao.a @LIBAO_LIBS@
+	       $(top_builddir)/libao/libao.a @LIBAO_LIBS@ -lm
 extract_a52_SOURCES = extract_a52.c getopt.c
 
 man_MANS = a52dec.1 extract_a52.1
--- a/liba52/Makefile.am
+++ b/liba52/Makefile.am
@@ -1,4 +1,4 @@
-CFLAGS = @CFLAGS@ @LIBA52_CFLAGS@
+AM_CFLAGS = @CFLAGS@ @LIBA52_CFLAGS@
 
 lib_LTLIBRARIES = liba52.la