diff --git a/configure.ac b/configure.ac
index 96c4cc5..29e11f9 100644
--- a/configure.ac
+++ b/configure.ac
@@ -69,6 +69,11 @@ AC_PROG_LIBTOOL
 dnl Check for math library
 AC_CHECK_LIB([m], [exp])
 
+AC_CHECK_LIB([amd], [amd_1])
+AC_CHECK_LIB([colamd], [colamd])
+AC_CHECK_HEADER([amd.h])
+AC_CHECK_LIB([z], [gzopen])
+
 dnl Check for <sys/time.h> header
 AC_CHECK_HEADER([sys/time.h],
    AC_DEFINE([HAVE_SYS_TIME_H], [1], [N/A]))
diff --git a/src/Makefile.am b/src/Makefile.am
index eb5dc1b..b814627 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -6,10 +6,8 @@ lib_LTLIBRARIES = libglpk.la
 
 libglpk_la_CPPFLAGS = \
 -I$(srcdir) \
--I$(srcdir)/amd \
 -I$(srcdir)/api \
 -I$(srcdir)/bflib \
--I$(srcdir)/colamd \
 -I$(srcdir)/draft \
 -I$(srcdir)/env \
 -I$(srcdir)/intopt \
@@ -18,8 +16,7 @@ libglpk_la_CPPFLAGS = \
 -I$(srcdir)/mpl \
 -I$(srcdir)/npp \
 -I$(srcdir)/proxy \
--I$(srcdir)/simplex \
--I$(srcdir)/zlib
+-I$(srcdir)/simplex
 
 libglpk_la_LDFLAGS = \
 -version-info 43:0:3 \
@@ -27,18 +24,6 @@ libglpk_la_LDFLAGS = \
 ${NOUNDEFINED}
 
 libglpk_la_SOURCES = \
-amd/amd_1.c \
-amd/amd_2.c \
-amd/amd_aat.c \
-amd/amd_control.c \
-amd/amd_defaults.c \
-amd/amd_dump.c \
-amd/amd_info.c \
-amd/amd_order.c \
-amd/amd_post_tree.c \
-amd/amd_postorder.c \
-amd/amd_preprocess.c \
-amd/amd_valid.c \
 api/advbas.c \
 api/asnhall.c \
 api/asnlp.c \
@@ -104,7 +89,6 @@ bflib/scf.c \
 bflib/scfint.c \
 bflib/sgf.c \
 bflib/sva.c \
-colamd/colamd.c \
 draft/bfd.c \
 draft/bfx.c \
 draft/glpapi06.c \
@@ -202,21 +186,6 @@ simplex/spxprim.c \
 simplex/spxprob.c \
 simplex/spychuzc.c \
 simplex/spychuzr.c \
-simplex/spydual.c \
-zlib/adler32.c \
-zlib/compress.c \
-zlib/crc32.c \
-zlib/deflate.c \
-zlib/gzclose.c \
-zlib/gzlib.c \
-zlib/gzread.c \
-zlib/gzwrite.c \
-zlib/inffast.c \
-zlib/inflate.c \
-zlib/inftrees.c \
-zlib/trees.c \
-zlib/uncompr.c \
-zlib/zio.c \
-zlib/zutil.c
+simplex/spydual.c
 
 ## eof ##