diff --git a/applications/smurf/libsmurf/smurf_makemap.c b/applications/smurf/libsmurf/smurf_makemap.c
index 675b93b99e2..bd45b8516da 100644
--- a/applications/smurf/libsmurf/smurf_makemap.c
+++ b/applications/smurf/libsmurf/smurf_makemap.c
@@ -746,7 +746,10 @@
 *        accessed (unless JSA tiles are being created).
 *     2014-03-31 (DSB):
 *        smf_mapbounds fast mode has been fixed so that it now works for
-#        the JSA all-sky pixel grid.
+*        the JSA all-sky pixel grid.
+*     2014-08-14 (DSB):
+*        Add NCHUNK item to the SMURF extension of the output map,
+*        holding the number of chunks used.
 *     {enter_further_changes_here}
 
 *  Copyright:
@@ -1824,6 +1827,10 @@ void smurf_makemap( int *status ) {
        ndfXpt0i( iters, ondf, SMURF__EXTNAME, "NUMITER", status );
     }
 
+    /* Store the number of chunks used in the smurf extension of the
+       output map. */
+    ndfXpt0i( (int) ncontchunks, ondf, SMURF__EXTNAME, "NCHUNK", status );
+
     /* Set bad bits mask to enable QUALITY. We can have quality bits set
        indicating where a boundary condition to zero the map has been used.
        If ast.zero_notlast is set the boundary condition was not applied on