diff --git a/src/mrw/checkcxx11.hxx b/src/mrw/checkcxx11.hxx
index cea03ae..f4ea966 100644
--- a/src/mrw/checkcxx11.hxx
+++ b/src/mrw/checkcxx11.hxx
@@ -19,17 +19,21 @@
             removed in future releases, when support for C++11 is more
             common. Only rely on this workaround, if you really have to. */
 #      define MRW__OLD_PRE11_COMPILER
-#      warning You need a C++11 compliant compiler, on gcc use option -std=c++11
+#      warning you need a C++11 compliant compiler, on gcc use option -std=c++11
 #      warning emulating C++11 - this changes the way you use the library
 #      warning this is deprecated and will be removed in future releases
 #      warning refere to the library documentation for more details
 #    endif
 #  endif
 
+#  if __cplusplus==1
+#    warning your compiler has a know bug, please upgrade
+#  endif
+
 
 #  ifdef MRW__OLD_PRE11_COMPILER
-#    if __cplusplus <= 199711
-#      warning compiler is older than 11/1997, emulate std::shared_ptr
+// __cplusplus==1 is a known bug in gcc 4.6.3
+#    if __cplusplus<200300L && __cplusplus!=1
 #      include <boost/shared_ptr.hpp>
 namespace std {
   // there is no std::shared_ptr in pre C++11 compilers, so we use the