diff --git a/opal/mca/pmix/pmix_types.h b/opal/mca/pmix/pmix_types.h
index 2ffa0bdd02..3f80b4e82d 100644
--- a/opal/mca/pmix/pmix_types.h
+++ b/opal/mca/pmix/pmix_types.h
@@ -95,6 +95,7 @@ BEGIN_C_DECLS
 /* size info */
 #define OPAL_PMIX_UNIV_SIZE                     "pmix.univ.size"        // (uint32_t) #procs in this nspace
 #define OPAL_PMIX_JOB_SIZE                      "pmix.job.size"         // (uint32_t) #procs in this job
+#define OPAL_PMIX_JOB_NUM_APPS                  "pmix.job.napps"        // (uint32_t) #apps in this job
 #define OPAL_PMIX_APP_SIZE                      "pmix.app.size"         // (uint32_t) #procs in this app
 #define OPAL_PMIX_LOCAL_SIZE                    "pmix.local.size"       // (uint32_t) #procs in this job on this node
 #define OPAL_PMIX_NODE_SIZE                     "pmix.node.size"        // (uint32_t) #procs across all jobs on this node
diff --git a/orte/orted/pmix/pmix_server_register_fns.c b/orte/orted/pmix/pmix_server_register_fns.c
index f6f7cf6132..849208d2e5 100644
--- a/orte/orted/pmix/pmix_server_register_fns.c
+++ b/orte/orted/pmix/pmix_server_register_fns.c
@@ -279,6 +279,13 @@ int orte_pmix_server_register_nspace(orte_job_t *jdata)
     kv->data.uint32 = jdata->num_procs;
     opal_list_append(info, &kv->super);
 
+    /* number of apps in this job */
+    kv = OBJ_NEW(opal_value_t);
+    kv->key = strdup(OPAL_PMIX_JOB_NUM_APPS);
+    kv->type = OPAL_UINT32;
+    kv->data.uint32 = jdata->num_apps;
+    opal_list_append(info, &kv->super);
+
     /* local size */
     kv = OBJ_NEW(opal_value_t);
     kv->key = strdup(OPAL_PMIX_LOCAL_SIZE);