diff --git a/C/arith1.c b/C/arith1.c
index 7ebdf980a..154f3a321 100644
--- a/C/arith1.c
+++ b/C/arith1.c
@@ -1381,11 +1381,14 @@ p_round(Term t E_ARGS)
       RERROR();
     }
   }
-
+  
   if (yap_flags[LANGUAGE_MODE_FLAG] == 1) { /* iso */
-    RBIG_FL(rint(dbl));
+    double vl = rint(dbl);
+    RBIG_FL(vl);
   } else {
-    RFLOAT(rint(dbl));
+    double vl = rint(dbl);
+    printf("vl is %d\n", vl);
+    RFLOAT(vl);
   }
 }
 
diff --git a/H/eval.h b/H/eval.h
index 85bcbf02d..992c300e6 100644
--- a/H/eval.h
+++ b/H/eval.h
@@ -18,7 +18,9 @@
 #include <stdlib.h>
 
 /* C library used to implement floating point functions */
+#if HAVE_MATH_H
 #include <math.h>
+#endif
 #if HAVE_IEEEFP_H
 #include <ieeefp.h>
 #endif
diff --git a/config.h.in b/config.h.in
index f017d0be7..882280535 100644
--- a/config.h.in
+++ b/config.h.in
@@ -59,6 +59,7 @@
 #undef  HAVE_IO_H
 #undef  HAVE_LIMITS_H
 #undef  HAVE_MALLOC_H
+#undef  HAVE_MATH_H
 #undef  HAVE_MEMORY_H
 #undef  HAVE_NETDB_H
 #undef  HAVE_NETINET_IN_H
@@ -238,9 +239,11 @@
 #define USE_SOCKET 1
 #endif
 
+#if defined(__hpux)
 /* HP-UX requires extra definitions for X/Open networking */
 #undef _XOPEN_SOURCE
 #define _XOPEN_SOURCE_EXTENDED 0
+#endif
 
 #if HAVE_GMP_H && HAVE_LIBGMP
 #define USE_GMP 1
diff --git a/configure b/configure
index 05e7a22c5..63b4896d4 100755
--- a/configure
+++ b/configure
@@ -5168,7 +5168,8 @@ done
 
 
 
-for ac_header in malloc.h memory.h
+
+for ac_header in malloc.h math.h memory.h
 do
 as_ac_Header=`echo "ac_cv_header_$ac_header" | $as_tr_sh`
 if eval "test \"\${$as_ac_Header+set}\" = set"; then
diff --git a/configure.in b/configure.in
index c4469f36c..26fa59386 100644
--- a/configure.in
+++ b/configure.in
@@ -583,7 +583,7 @@ AC_HEADER_SYS_WAIT
 AC_CHECK_HEADERS(arpa/inet.h ctype.h direct.h dirent.h dlfcn.h)
 AC_CHECK_HEADERS(errno.h fcntl.h)
 AC_CHECK_HEADERS(fenv.h fpu_control.h ieeefp.h io.h limits.h)
-AC_CHECK_HEADERS(malloc.h memory.h)
+AC_CHECK_HEADERS(malloc.h math.h memory.h)
 AC_CHECK_HEADERS(netdb.h netinet/in.h regex.h)
 AC_CHECK_HEADERS(siginfo.h signal.h stdarg.h string.h stropts.h)
 AC_CHECK_HEADERS(sys/conf.h sys/file.h)