diff --git a/configure b/configure
index 0b4f7aef76a1a233a818fd471bc1f442d76f492b..1be0621d3ef4171955ad0b6eceb7c01f6b673587 100755
--- a/configure
+++ b/configure
@@ -5075,14 +5075,25 @@ main ()
 _ACEOF
 if ac_fn_cxx_try_compile "$LINENO"; then :
   { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
+$as_echo "yes" >&6; };
+  support_cxx11=true
 else
   { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
 $as_echo "no" >&6; } ;
-   as_fn_error $? "C++11 support is required" "$LINENO" 5
+  support_cxx11=false
 fi
 rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
 
+if test "$support_cxx11" = false
+then
+   { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: C++11 support is required as of PLUMED 2.4" >&5
+$as_echo "$as_me: WARNING: C++11 support is required as of PLUMED 2.4" >&2;}
+   { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: your compiler appears not to support C++11" >&5
+$as_echo "$as_me: WARNING: your compiler appears not to support C++11" >&2;}
+   { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: please change compiler of make sure that everything works correctly" >&5
+$as_echo "$as_me: WARNING: please change compiler of make sure that everything works correctly" >&2;}
+fi
+
 
 
 
diff --git a/configure.ac b/configure.ac
index be80486cdf7ff2a14bf00375e621c8396ba4cbf8..2d6938893020ad5f20af54e17f8141ace3ae2d55 100644
--- a/configure.ac
+++ b/configure.ac
@@ -288,9 +288,17 @@ AC_COMPILE_IFELSE([AC_LANG_PROGRAM([
 this_compiler_does_not_support_cxx11
 #endif
 ])],
-  [AC_MSG_RESULT([yes])],
+  [AC_MSG_RESULT([yes])];
+  support_cxx11=true,
   [AC_MSG_RESULT([no]) ;
-   AC_MSG_ERROR([C++11 support is required])])
+  support_cxx11=false])
+
+if test "$support_cxx11" = false
+then
+   AC_MSG_WARN([C++11 support is required as of PLUMED 2.4])
+   AC_MSG_WARN([your compiler appears not to support C++11])
+   AC_MSG_WARN([please change compiler of make sure that everything works correctly])
+fi