diff --git a/configure b/configure
index d374e8dadb1736926d579b93072134e20f35ef7d..605ef4e0b6e8078f72e1287f32294986b6d20556 100755
--- a/configure
+++ b/configure
@@ -6266,9 +6266,12 @@ if test $mpi == true; then
     { $as_echo "$as_me:${as_lineno-$LINENO}: **** PLUMED will be compiled using MPI" >&5
 $as_echo "$as_me: **** PLUMED will be compiled using MPI" >&6;}
   else
-    { $as_echo "$as_me:${as_lineno-$LINENO}: **** PLUMED will NOT be compiled using MPI" >&5
-$as_echo "$as_me: **** PLUMED will NOT be compiled using MPI" >&6;}
+    { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: **** PLUMED will NOT be compiled using MPI because MPI have not been found!" >&5
+$as_echo "$as_me: WARNING: **** PLUMED will NOT be compiled using MPI because MPI have not been found!" >&2;}
   fi
+else
+    { $as_echo "$as_me:${as_lineno-$LINENO}: **** PLUMED will be compiled without MPI" >&5
+$as_echo "$as_me: **** PLUMED will be compiled without MPI" >&6;}
 fi
 
 
diff --git a/configure.ac b/configure.ac
index 2a6a5dbb5d4687174970563032e65ae6d88afb1f..9d20c93d1aad479be21338712f4b02666823102a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -510,8 +510,10 @@ if test $mpi == true; then
   if test $mpi_found == ok; then
     AC_MSG_NOTICE([**** PLUMED will be compiled using MPI])
   else 
-    AC_MSG_NOTICE([**** PLUMED will NOT be compiled using MPI])
+    AC_MSG_WARN([**** PLUMED will NOT be compiled using MPI because MPI have not been found!])
   fi
+else
+    AC_MSG_NOTICE([**** PLUMED will be compiled without MPI])
 fi
 
 AC_SUBST(build_dir)