diff -Naur HDF4.2r4/mfhdf/hdiff/Makefile.am HDF4.2r4.oden/mfhdf/hdiff/Makefile.am
--- HDF4.2r4/mfhdf/hdiff/Makefile.am	2008-10-14 23:51:03.000000000 +0200
+++ HDF4.2r4.oden/mfhdf/hdiff/Makefile.am	2009-08-17 13:31:37.000000000 +0200
@@ -34,7 +34,7 @@
 noinst_PROGRAMS = hdifftst
 
 hdifftst_SOURCES = hdifftst.c
-hdifftst_LDADD = ../libsrc/libmfhdf.la $(top_builddir)/hdf/src/libdf.la
+hdifftst_LDADD = ../libsrc/libmfhdf.la $(top_builddir)/hdf/src/libdf.la -lm
 hdifftst_DEPENDENCIES = $(top_builddir)/hdf/src/libdf.la ../libsrc/libmfhdf.la
 
 check: hdifftst
diff -Naur HDF4.2r4/mfhdf/hdiff/Makefile.in HDF4.2r4.oden/mfhdf/hdiff/Makefile.in
--- HDF4.2r4/mfhdf/hdiff/Makefile.in	2008-10-14 23:51:03.000000000 +0200
+++ HDF4.2r4.oden/mfhdf/hdiff/Makefile.in	2009-08-17 13:35:27.000000000 +0200
@@ -121,7 +121,7 @@
 LEXLIB = @LEXLIB@
 LEX_OUTPUT_ROOT = @LEX_OUTPUT_ROOT@
 LIBOBJS = @LIBOBJS@
-LIBS = @LIBS@
+LIBS = @LIBS@ -lm
 LIBTOOL = @LIBTOOL@
 LIPO = @LIPO@
 LN_S = @LN_S@
diff -Naur HDF4.2r4/mfhdf/hrepack/Makefile.in HDF4.2r4.oden/mfhdf/hrepack/Makefile.in
--- HDF4.2r4/mfhdf/hrepack/Makefile.in	2008-11-18 22:40:10.000000000 +0100
+++ HDF4.2r4.oden/mfhdf/hrepack/Makefile.in	2009-08-17 13:33:44.000000000 +0200
@@ -138,7 +138,7 @@
 LEXLIB = @LEXLIB@
 LEX_OUTPUT_ROOT = @LEX_OUTPUT_ROOT@
 LIBOBJS = @LIBOBJS@
-LIBS = @LIBS@
+LIBS = @LIBS@ -lm
 LIBTOOL = @LIBTOOL@
 LIPO = @LIPO@
 LN_S = @LN_S@
diff -Naur HDF4.2r4/mfhdf/Makefile.in HDF4.2r4.oden/mfhdf/Makefile.in
--- HDF4.2r4/mfhdf/Makefile.in	2008-10-13 21:39:11.000000000 +0200
+++ HDF4.2r4.oden/mfhdf/Makefile.in	2009-08-17 13:32:16.000000000 +0200
@@ -103,7 +103,7 @@
 LEXLIB = @LEXLIB@
 LEX_OUTPUT_ROOT = @LEX_OUTPUT_ROOT@
 LIBOBJS = @LIBOBJS@
-LIBS = @LIBS@
+LIBS = @LIBS@ -lm
 LIBTOOL = @LIBTOOL@
 LIPO = @LIPO@
 LN_S = @LN_S@