diff --git a/config/lyxinclude.m4 b/config/lyxinclude.m4
index e532c54d87..2e529ea221 100644
--- a/config/lyxinclude.m4
+++ b/config/lyxinclude.m4
@@ -232,6 +232,10 @@ AC_ARG_ENABLE(pch,
 	enable_pch=no;)
 lyx_pch_comp=no
 
+AC_ARG_ENABLE(cxx11,
+  AC_HELP_STRING([--enable-cxx11],[enable C++11 mode]),,
+  enable_cxx11=no;)
+
 AC_ARG_ENABLE(assertions,
   AC_HELP_STRING([--enable-assertions],[add runtime sanity checks in the program]),,
   [AS_CASE([$build_type], [dev*|pre*], [enable_assertions=yes],
@@ -306,6 +310,18 @@ if test x$GXX = xyes; then
 	;;
     esac
   fi
+  if test x$enable_cxx11 = xyes ; then
+      case $gxx_version in
+	  4.3*|4.4*|4.5*|4.6*)
+	      lyx_flags="$lyx_flags c++11-mode"
+	      CXXFLAGS="-std=gnu++0x $CXXFLAGS"
+	      ;;
+	  4.7*|4.8*)
+	      lyx_flags="$lyx_flags c++11-mode"
+	      CXXFLAGS="-std=gnu++11 $CXXFLAGS"
+	      ;;
+      esac
+  fi
 fi
 test "$lyx_pch_comp" = yes && lyx_flags="$lyx_flags pch"
 AM_CONDITIONAL(LYX_BUILD_PCH, test "$lyx_pch_comp" = yes)
diff --git a/src/support/Messages.cpp b/src/support/Messages.cpp
index ca5c110913..fdcaf6645c 100644
--- a/src/support/Messages.cpp
+++ b/src/support/Messages.cpp
@@ -119,7 +119,7 @@ bool Messages::available(string const & c)
 	// this loops at most twice
 	while (true) {
 		string const filen = locale_dir + "/" + code 
-			+ "/LC_MESSAGES/"PACKAGE".mo";
+			+ "/LC_MESSAGES/" PACKAGE ".mo";
 		if (FileName(filen).isReadableFile())
 			return true;
 		if (contains(code, '_'))