diff --git a/orte/mca/rmaps/ppr/rmaps_ppr.c b/orte/mca/rmaps/ppr/rmaps_ppr.c
index 767e1134e3..000dcbb529 100644
--- a/orte/mca/rmaps/ppr/rmaps_ppr.c
+++ b/orte/mca/rmaps/ppr/rmaps_ppr.c
@@ -3,6 +3,8 @@
  * Copyright (c) 2011      Los Alamos National Security, LLC.
  *                         All rights reserved.
  * Copyright (c) 2014-2015 Intel, Inc. All rights reserved.
+ * Copyright (c) 2015      Research Organization for Information Science
+ *                         and Technology (RIST). All rights reserved.
  * $COPYRIGHT$
  *
  * Additional copyrights may follow
@@ -346,6 +348,22 @@ static int ppr_mapper(orte_job_t *jdata)
                  * properly set
                  */
                 ORTE_FLAG_SET(node, ORTE_NODE_FLAG_OVERSUBSCRIBED);
+                /* check for permission */
+                if (ORTE_FLAG_TEST(node, ORTE_NODE_FLAG_SLOTS_GIVEN)) {
+                    /* if we weren't given a directive either way, then we will error out
+                     * as the #slots were specifically given, either by the host RM or
+                     * via hostfile/dash-host */
+                    if (!(ORTE_MAPPING_SUBSCRIBE_GIVEN & ORTE_GET_MAPPING_DIRECTIVE(orte_rmaps_base.mapping))) {
+                        orte_show_help("help-orte-rmaps-base.txt", "orte-rmaps-base:alloc-error",
+                                       true, app->num_procs, app->app);
+                        return ORTE_ERR_SILENT;
+                    } else if (ORTE_MAPPING_NO_OVERSUBSCRIBE & ORTE_GET_MAPPING_DIRECTIVE(jdata->map->mapping)) {
+                        /* if we were explicitly told not to oversubscribe, then don't */
+                        orte_show_help("help-orte-rmaps-base.txt", "orte-rmaps-base:alloc-error",
+                                       true, app->num_procs, app->app);
+                        return ORTE_ERR_SILENT;
+                    }
+                }
             }
 
             /* if we haven't mapped all the procs, continue on to the
diff --git a/orte/mca/rmaps/round_robin/rmaps_rr_mappers.c b/orte/mca/rmaps/round_robin/rmaps_rr_mappers.c
index 0cb4044059..4b821308c2 100644
--- a/orte/mca/rmaps/round_robin/rmaps_rr_mappers.c
+++ b/orte/mca/rmaps/round_robin/rmaps_rr_mappers.c
@@ -11,6 +11,8 @@
  *                         All rights reserved.
  * Copyright (c) 2009-2013 Cisco Systems, Inc.  All rights reserved.
  * Copyright (c) 2013-2015 Intel, Inc. All rights reserved.
+ * Copyright (c) 2015      Research Organization for Information Science
+ *                         and Technology (RIST). All rights reserved.
  * $COPYRIGHT$
  *
  * Additional copyrights may follow
@@ -184,6 +186,22 @@ int orte_rmaps_rr_byslot(orte_job_t *jdata,
              * properly set
              */
             ORTE_FLAG_SET(node, ORTE_NODE_FLAG_OVERSUBSCRIBED);
+            /* check for permission */
+            if (ORTE_FLAG_TEST(node, ORTE_NODE_FLAG_SLOTS_GIVEN)) {
+                /* if we weren't given a directive either way, then we will error out
+                 * as the #slots were specifically given, either by the host RM or
+                 * via hostfile/dash-host */
+                if (!(ORTE_MAPPING_SUBSCRIBE_GIVEN & ORTE_GET_MAPPING_DIRECTIVE(orte_rmaps_base.mapping))) {
+                    orte_show_help("help-orte-rmaps-base.txt", "orte-rmaps-base:alloc-error",
+                                   true, app->num_procs, app->app);
+                    return ORTE_ERR_SILENT;
+                } else if (ORTE_MAPPING_NO_OVERSUBSCRIBE & ORTE_GET_MAPPING_DIRECTIVE(jdata->map->mapping)) {
+                    /* if we were explicitly told not to oversubscribe, then don't */
+                    orte_show_help("help-orte-rmaps-base.txt", "orte-rmaps-base:alloc-error",
+                                   true, app->num_procs, app->app);
+                    return ORTE_ERR_SILENT;
+                }
+            }
         }
         /* if we have mapped everything, then we are done */
         if (nprocs_mapped == app->num_procs) {
@@ -349,6 +367,22 @@ int orte_rmaps_rr_bynode(orte_job_t *jdata,
                  * properly set
                  */
                 ORTE_FLAG_SET(node, ORTE_NODE_FLAG_OVERSUBSCRIBED);
+                /* check for permission */
+                if (ORTE_FLAG_TEST(node, ORTE_NODE_FLAG_SLOTS_GIVEN)) {
+                    /* if we weren't given a directive either way, then we will error out
+                     * as the #slots were specifically given, either by the host RM or
+                     * via hostfile/dash-host */
+                    if (!(ORTE_MAPPING_SUBSCRIBE_GIVEN & ORTE_GET_MAPPING_DIRECTIVE(orte_rmaps_base.mapping))) {
+                        orte_show_help("help-orte-rmaps-base.txt", "orte-rmaps-base:alloc-error",
+                                       true, app->num_procs, app->app);
+                        return ORTE_ERR_SILENT;
+                    } else if (ORTE_MAPPING_NO_OVERSUBSCRIBE & ORTE_GET_MAPPING_DIRECTIVE(jdata->map->mapping)) {
+                        /* if we were explicitly told not to oversubscribe, then don't */
+                        orte_show_help("help-orte-rmaps-base.txt", "orte-rmaps-base:alloc-error",
+                                       true, app->num_procs, app->app);
+                        return ORTE_ERR_SILENT;
+                    }
+                }
             }
             if (nprocs_mapped == app->num_procs) {
                 /* we are done */
@@ -550,6 +584,22 @@ int orte_rmaps_rr_byobj(orte_job_t *jdata,
                  * properly set
                  */
                 ORTE_FLAG_SET(node, ORTE_NODE_FLAG_OVERSUBSCRIBED);
+                /* check for permission */
+                if (ORTE_FLAG_TEST(node, ORTE_NODE_FLAG_SLOTS_GIVEN)) {
+                    /* if we weren't given a directive either way, then we will error out
+                     * as the #slots were specifically given, either by the host RM or
+                     * via hostfile/dash-host */
+                    if (!(ORTE_MAPPING_SUBSCRIBE_GIVEN & ORTE_GET_MAPPING_DIRECTIVE(orte_rmaps_base.mapping))) {
+                        orte_show_help("help-orte-rmaps-base.txt", "orte-rmaps-base:alloc-error",
+                                       true, app->num_procs, app->app);
+                        return ORTE_ERR_SILENT;
+                    } else if (ORTE_MAPPING_NO_OVERSUBSCRIBE & ORTE_GET_MAPPING_DIRECTIVE(jdata->map->mapping)) {
+                        /* if we were explicitly told not to oversubscribe, then don't */
+                        orte_show_help("help-orte-rmaps-base.txt", "orte-rmaps-base:alloc-error",
+                                       true, app->num_procs, app->app);
+                        return ORTE_ERR_SILENT;
+                    }
+                }
             }
             if (nprocs_mapped == app->num_procs) {
                 /* we are done */
diff --git a/orte/mca/rmaps/seq/rmaps_seq.c b/orte/mca/rmaps/seq/rmaps_seq.c
index ea70d8abd5..d08fe589e0 100644
--- a/orte/mca/rmaps/seq/rmaps_seq.c
+++ b/orte/mca/rmaps/seq/rmaps_seq.c
@@ -370,6 +370,22 @@ static int orte_rmaps_seq_map(orte_job_t *jdata)
                  * properly set
                  */
                 ORTE_FLAG_SET(node, ORTE_NODE_FLAG_OVERSUBSCRIBED);
+                /* check for permission */
+                if (ORTE_FLAG_TEST(node, ORTE_NODE_FLAG_SLOTS_GIVEN)) {
+                    /* if we weren't given a directive either way, then we will error out
+                     * as the #slots were specifically given, either by the host RM or
+                     * via hostfile/dash-host */
+                    if (!(ORTE_MAPPING_SUBSCRIBE_GIVEN & ORTE_GET_MAPPING_DIRECTIVE(orte_rmaps_base.mapping))) {
+                        orte_show_help("help-orte-rmaps-base.txt", "orte-rmaps-base:alloc-error",
+                                       true, app->num_procs, app->app);
+                        return ORTE_ERR_SILENT;
+                    } else if (ORTE_MAPPING_NO_OVERSUBSCRIBE & ORTE_GET_MAPPING_DIRECTIVE(jdata->map->mapping)) {
+                        /* if we were explicitly told not to oversubscribe, then don't */
+                        orte_show_help("help-orte-rmaps-base.txt", "orte-rmaps-base:alloc-error",
+                                       true, app->num_procs, app->app);
+                        return ORTE_ERR_SILENT;
+                    }
+                }
             }
             /* assign the vpid */
             proc->name.vpid = vpid++;