diff --git a/include/boost/iostreams/detail/vc6/read.hpp b/include/boost/iostreams/detail/vc6/read.hpp
index 2a9c235..6e9cddf 100755
--- a/include/boost/iostreams/detail/vc6/read.hpp
+++ b/include/boost/iostreams/detail/vc6/read.hpp
@@ -144,7 +144,7 @@ struct read_device_impl<streambuf_tag> {
         {
             typedef typename char_type_of<T>::type  char_type;
             typedef char_traits<char_type>          traits_type;
-            return !traits_type::is_eof(t.sputbackc());
+            return !traits_type::is_eof(t.sputbackc(c));
         }
     };
 };
diff --git a/include/boost/iostreams/read.hpp b/include/boost/iostreams/read.hpp
index 590ccd2..8ea2e6e 100755
--- a/include/boost/iostreams/read.hpp
+++ b/include/boost/iostreams/read.hpp
@@ -158,7 +158,7 @@ struct read_device_impl<streambuf_tag> {
     {   // gcc 2.95 needs namespace qualification for char_traits.
         typedef typename char_type_of<T>::type     char_type;
         typedef iostreams::char_traits<char_type>  traits_type;
-        return !traits_type::is_eof(t.sputbackc());
+        return !traits_type::is_eof(t.sputbackc(c));
     }
 };