Index: boost/spirit/home/karma/numeric/detail/numeric_utils.hpp
===================================================================
--- boost/spirit/home/karma/numeric/detail/numeric_utils.hpp	(revision 81163)
+++ boost/spirit/home/karma/numeric/detail/numeric_utils.hpp	(working copy)
@@ -545,6 +545,31 @@
             return call(n, mpl::bool_<is_integral<T>::value>());
         }
     };
+
+    ///////////////////////////////////////////////////////////////////////
+    struct decompose_real
+    {
+        template <typename T>
+        static T call(T n, T* iptr, mpl::true_)
+        {
+            *iptr = n;
+            return T(0);
+        }
+
+        template <typename T>
+        static T call(T n, T* iptr, mpl::false_)
+        {
+            // Allow ADL to find the correct overload for modf
+            using namespace std; 
+            return modf(n, iptr);
+        }
+
+        template <typename T>
+        static T call(T n, T* iptr)
+        {
+            return call(n, iptr, mpl::bool_<is_integral<T>::value>());
+        }
+    };
 }}}
 
 namespace boost { namespace spirit { namespace karma
Index: boost/spirit/home/karma/numeric/detail/real_utils.hpp
===================================================================
--- boost/spirit/home/karma/numeric/detail/real_utils.hpp	(revision 81163)
+++ boost/spirit/home/karma/numeric/detail/real_utils.hpp	(working copy)
@@ -112,7 +112,7 @@
         // prepare numbers (sign, integer and fraction part)
             U integer_part;
             U precexp = spirit::traits::pow10<U>(precision);
-            U fractional_part = modf(n, &integer_part);
+            U fractional_part = spirit::traits::decompose_real::call(n, &integer_part);
 
             fractional_part = floor(fractional_part * precexp + U(0.5));
             if (fractional_part >= precexp)