diff --git a/src/CoinFinite.cpp b/src/CoinFinite.cpp
index c23690f8a..81b0e2127 100644
--- a/src/CoinFinite.cpp
+++ b/src/CoinFinite.cpp
@@ -3,35 +3,17 @@
 // This code is licensed under the terms of the Eclipse Public License (EPL).
 
 #include "CoinFinite.hpp"
-#include "CoinUtilsConfig.h"
 
-#include <cfloat>
 #include <cmath>
 
-#ifdef HAVE_CIEEEFP
-#include <cieeefp>
-#else
-#ifdef HAVE_IEEEFP_H
-#include <ieeefp.h>
-#endif
-#endif
-
 bool CoinFinite(double val)
 {
-#ifdef COINUTILS_C_FINITE
-  return COINUTILS_C_FINITE(val) != 0;
-#else
-  return val != COIN_DBL_MAX && val != -COIN_DBL_MAX;
-#endif
+  return std::isfinite(val);
 }
 
 bool CoinIsnan(double val)
 {
-#ifdef COINUTILS_C_ISNAN
-  return COINUTILS_C_ISNAN(val) != 0;
-#else
-  return false;
-#endif
+  return std::isnan(val);
 }
 
 /* vi: softtabstop=2 shiftwidth=2 expandtab tabstop=2
diff --git a/test/CoinPackedVectorTest.cpp b/test/CoinPackedVectorTest.cpp
index 7b9bc18b1..ae5b7cbb7 100644
--- a/test/CoinPackedVectorTest.cpp
+++ b/test/CoinPackedVectorTest.cpp
@@ -685,13 +685,9 @@ CoinPackedVectorUnitTest()
     int inx2[ne2] =   { 7,  4,  2,  1  };
     double el2[ne2] = { 7., 4., 2., 1. };
 
-#   ifdef COINUTILS_C_FINITE
     double one = 1.0 ;
     double zero = 0.0 ;
     double infty = one/zero ;
-#   else
-    double infty = COIN_DBL_MAX ;
-#   endif
 
     CoinPackedVector v1;
     CoinPackedVector v2;
@@ -702,11 +698,9 @@ CoinPackedVectorUnitTest()
     rV.setConstant(ne1,inx1,0) ;
     r = v2 / v1;
     assert(r.isEquivalent(rV)) ;
-#  ifdef COINUTILS_C_FINITE
     rV.setConstant(ne1,inx1,infty) ;
     r = v1 / v2;
     assert(r.isEquivalent(rV)) ;
-#   endif
     
     r.isEquivalent(rV) ;
 
diff --git a/test/unitTest.cpp b/test/unitTest.cpp
index acae47328..0b790df61 100644
--- a/test/unitTest.cpp
+++ b/test/unitTest.cpp
@@ -136,11 +136,7 @@ int main (int argc, const char *argv[])
   double checkVal ;
 
   testingMessage( "Testing CoinFinite ... " ) ;
-# ifdef COINUTILS_C_FINITE
   checkVal = finiteVal/zero ;
-# else
-  checkVal = COIN_DBL_MAX ;
-# endif
   testingMessage( " finite value: " ) ;
   if (CoinFinite(finiteVal))
   { testingMessage( "ok" ) ; }
@@ -154,11 +150,8 @@ int main (int argc, const char *argv[])
   else
   { allOK = false ;
     testingMessage( "ERROR.\n" ) ; }
-#else
-#undef COINUTILS_C_FINITE
 #endif
 
-# ifdef COINUTILS_C_ISNAN
   testingMessage( "Testing CoinIsnan ... " ) ;
   testingMessage( " finite value: " ) ;
   if (!CoinIsnan(finiteVal))
@@ -167,19 +160,12 @@ int main (int argc, const char *argv[])
   { allOK = false ;
     testingMessage( "ERROR" ) ; }
   testingMessage( "; NaN value: " ) ;
-# ifdef COINUTILS_C_FINITE
   checkVal = checkVal/checkVal ;
   if (CoinIsnan(checkVal))
   { testingMessage( "ok.\n" ) ; }
   else
   { allOK = false ;
     testingMessage( "ERROR.\n" ) ; }
-# endif
-# else
-  allOK = false ;
-  testingMessage( "ERROR: No functional CoinIsnan.\n" ) ;
-# endif
-
 
   if (netlibDir != "" && mpsDir != "" && testModel != ""){
      testingMessage( "Testing CoinModel\n" );