diff -Naur source.orig/utils/pmx/configure.ac source/utils/pmx/configure.ac
--- source.orig/utils/pmx/configure.ac	2014-11-17 07:28:11.000000000 -0500
+++ source/utils/pmx/configure.ac	2015-02-18 16:30:39.893003633 -0500
@@ -32,6 +33,7 @@
 AC_PROG_LN_S
 AC_PROG_MAKE_SET
 AC_PROG_RANLIB
+AC_CHECK_FUNCS([abs])
 
 AC_SEARCH_LIBS([sqrt], [m])
 
diff -Naur source.orig/utils/pmx/pmx-2.7.0/libf2c/f2c.h source/utils/pmx/pmx-2.7.0/libf2c/f2c.h
--- source.orig/utils/pmx/pmx-2.7.0/libf2c/f2c.h	2013-01-18 02:59:22.000000000 -0500
+++ source/utils/pmx/pmx-2.7.0/libf2c/f2c.h	2015-02-18 16:32:58.491994029 -0500
@@ -162,7 +164,9 @@
 	};
 typedef struct Namelist Namelist;
 
+#ifndef HAVE_ABS
 #define abs(x) ((x) >= 0 ? (x) : -(x))
+#endif
 #define dabs(x) (doublereal)abs(x)
 #undef  min
 #undef  max