diff --git a/hash/test/Jamfile.v2 b/hash/test/Jamfile.v2
index ff149a7..c91691f 100644
--- a/hash/test/Jamfile.v2
+++ b/hash/test/Jamfile.v2
@@ -38,6 +38,7 @@ test-suite functional/hash
         [ run link_ext_test.cpp link_no_ext_test.cpp ]
         [ run container_fwd_test.cpp ]
         [ compile-fail hash_no_ext_fail_test.cpp ]
+        [ compile-fail namespace_fail_test.cpp ]
         [ run hash_no_ext_macro_1.cpp ]
         [ run hash_no_ext_macro_2.cpp ]
     ;
diff --git a/hash/test/namespace_fail_test.cpp b/hash/test/namespace_fail_test.cpp
new file mode 100644
index 0000000..2e02d57
--- /dev/null
+++ b/hash/test/namespace_fail_test.cpp
@@ -0,0 +1,6 @@
+#include <list>
+#include <boost/functional/hash/detail/float_functions.hpp>
+
+typedef list<int> foo;
+
+int main() {}
\ No newline at end of file
diff --git a/include/boost/functional/hash/detail/float_functions.hpp b/include/boost/functional/hash/detail/float_functions.hpp
index 9ec0dd2..f766ec9 100644
--- a/include/boost/functional/hash/detail/float_functions.hpp
+++ b/include/boost/functional/hash/detail/float_functions.hpp
@@ -118,44 +118,46 @@ namespace boost {                                                       \
                 BOOST_STATIC_CONSTANT(bool, c99 =                       \
                     sizeof(float_type(c99_func(x,y)))                   \
                         == sizeof(is<type1>));                          \
-            };                                                          \
-                                                                        \
-            template <bool x>                                           \
-            struct call_c99 :                                           \
-                boost::hash_detail::call_##cpp_func<double> {};         \
-                                                                        \
-            template <>                                                 \
-            struct call_c99<true> {                                     \
-                typedef type1 float_type;                               \
-                                                                        \
-                template <typename T>                                   \
-                inline type1 operator()(type1 a, T b)  const            \
-                {                                                       \
-                    return c99_func(a, b);                              \
-                }                                                       \
-            };                                                          \
-                                                                        \
-            template <bool x>                                           \
-            struct call_cpp :                                           \
-                call_c99<                                               \
-                    ::boost::hash_detail::c99_func##_detect::check::c99 \
-                > {};                                                   \
-                                                                        \
-            template <>                                                 \
-            struct call_cpp<true> {                                     \
-                typedef type1 float_type;                               \
-                                                                        \
-                template <typename T>                                   \
-                inline type1 operator()(type1 a, T b)  const            \
-                {                                                       \
-                    return cpp_func(a, b);                              \
-                }                                                       \
             };                                                          \
         }                                                               \
                                                                         \
+        template <bool x>                                               \
+        struct call_c99_##c99_func :                                    \
+            boost::hash_detail::call_##cpp_func<double> {};             \
+                                                                        \
+        template <>                                                     \
+        struct call_c99_##c99_func<true> {                              \
+            typedef type1 float_type;                                   \
+                                                                        \
+            template <typename T>                                       \
+            inline type1 operator()(type1 a, T b)  const                \
+            {                                                           \
+                using namespace std;                                    \
+                return c99_func(a, b);                                  \
+            }                                                           \
+        };                                                              \
+                                                                        \
+        template <bool x>                                               \
+        struct call_cpp_##c99_func :                                    \
+            call_c99_##c99_func<                                        \
+                ::boost::hash_detail::c99_func##_detect::check::c99     \
+            > {};                                                       \
+                                                                        \
+        template <>                                                     \
+        struct call_cpp_##c99_func<true> {                              \
+            typedef type1 float_type;                                   \
+                                                                        \
+            template <typename T>                                       \
+            inline type1 operator()(type1 a, T b)  const                \
+            {                                                           \
+                using namespace std;                                    \
+                return cpp_func(a, b);                                  \
+            }                                                           \
+        };                                                              \
+                                                                        \
         template <>                                                     \
         struct call_##cpp_func<type1> :                                 \
-            c99_func##_detect::call_cpp<                                \
+            call_cpp_##c99_func<                                        \
                 ::boost::hash_detail::c99_func##_detect::check::cpp     \
             > {};                                                       \
     }                                                                   \