diff --git a/NEWS b/NEWS
index 0997630454..4eab3f17c8 100644
--- a/NEWS
+++ b/NEWS
@@ -64,6 +64,8 @@ Trunk (not on release branches yet)
 - Modified paffinity system to provide warning when bindings result in
   being "bound to all", which is equivalent to "not bound"
 - Added MPI-3 function: MPI_GET_LIBRARY_VERSION.
+- Enabled compile-time warning of deprecated MPI functions by default
+  (in supported compilers).
 
 
 1.5.5
diff --git a/README b/README
index 00742f94e4..c0c89541e0 100644
--- a/README
+++ b/README
@@ -444,6 +444,20 @@ MPI Functionality and Features
   it to printf for other MPI functions.  Patches and/or suggestions
   would be greatfully appreciated on the Open MPI developer's list.
 
+- When using MPI deprecated functions, some compilers will emit
+  warnings.  For example:
+
+  $ cat my_mpi_func.c
+  #include <mpi.h>
+  void foo(void) {
+      MPI_Datatype type;
+      MPI_Type_struct(1, NULL, NULL, NULL, &type);
+  }
+  $ mpicc -c my_mpi_func.c
+  my_mpi_func.c: In function 'foo':
+  my_mpi_func.c:4: warning: 'MPI_Type_struct' is deprecated (declared at /opt/openmpi/include/mpi.h:1522)
+
+
 Collectives
 -----------
 
diff --git a/ompi/config/ompi_configure_options.m4 b/ompi/config/ompi_configure_options.m4
index 7ebb32a455..536022469a 100644
--- a/ompi/config/ompi_configure_options.m4
+++ b/ompi/config/ompi_configure_options.m4
@@ -28,17 +28,18 @@ AC_DEFUN([OMPI_CONFIGURE_OPTIONS],[
 ompi_show_subtitle "OMPI Configuration options"
 
 #
-# Do we want to enable MPI interface warnings (e.g. deprecated functionality and others)?
+# Do we want to enable MPI interface warnings (e.g. deprecated
+# functionality and others)?
 #
-# XXX This __disabled__ by default for 1.5, but will be __enabled__ for 1.7 by default
-# Users should be notified about this proposed change.
+# This was disabled by default in v1.5, but will be enabled by default
+# in 1.7 and beyond.
 #
 
 AC_MSG_CHECKING([if want compile-time warnings inside of mpi.h])
 AC_ARG_ENABLE(mpi-interface-warning,
     AC_HELP_STRING([--enable-mpi-interface-warning],
                    [enable warnings in wrong (e.g. deprecated) usage in user-level code (default: disabled)]))
-if test "$enable_mpi_interface_warning" = "yes"; then
+if test "$enable_mpi_interface_warning" != "no"; then
     AC_MSG_RESULT([yes])
     OMPI_WANT_MPI_INTERFACE_WARNING=1
 else
@@ -46,7 +47,7 @@ else
     OMPI_WANT_MPI_INTERFACE_WARNING=0
 fi
 AC_DEFINE_UNQUOTED([OMPI_WANT_MPI_INTERFACE_WARNING], [$OMPI_WANT_MPI_INTERFACE_WARNING],
-    [Enable warnings in wrong usage (e.g. deprecated) in user-level code])
+    [Enable warnings when using deprecated MPI functions])
 
 #
 # Sparse Groups