diff --git a/opal/mca/pmix/pmix2x/pmix2x_client.c b/opal/mca/pmix/pmix2x/pmix2x_client.c
index 990be35666..52d77fab99 100644
--- a/opal/mca/pmix/pmix2x/pmix2x_client.c
+++ b/opal/mca/pmix/pmix2x/pmix2x_client.c
@@ -3,7 +3,7 @@
  * Copyright (c) 2014-2017 Intel, Inc.  All rights reserved.
  * Copyright (c) 2014-2017 Research Organization for Information Science
  *                         and Technology (RIST). All rights reserved.
- * Copyright (c) 2014-2015 Mellanox Technologies, Inc.
+ * Copyright (c) 2014-2017 Mellanox Technologies, Inc.
  *                         All rights reserved.
  * Copyright (c) 2016 Cisco Systems, Inc.  All rights reserved.
  * Copyright (c) 2016      Los Alamos National Security, LLC. All rights
@@ -78,8 +78,9 @@ int pmix2x_client_init(opal_list_t *ilist)
             asprintf(&dbgvalue, "PMIX_DEBUG=%d", dbg);
             putenv(dbgvalue);
         }
-        if (NULL != (evar = getenv("OPAL_PREFIX"))) {
-            opal_setenv("PMIX_PREFIX", evar, false, &environ);
+        if ((NULL != (evar = getenv("OPAL_PREFIX"))) && 
+            (NULL == getenv("PMIX_INSTALL_PREFIX"))) {
+            opal_setenv("PMIX_INSTALL_PREFIX", evar, false, &environ);
         }
     }
 
diff --git a/opal/mca/pmix/pmix2x/pmix2x_server_south.c b/opal/mca/pmix/pmix2x/pmix2x_server_south.c
index 0842b3918a..41abb8b4d5 100644
--- a/opal/mca/pmix/pmix2x/pmix2x_server_south.c
+++ b/opal/mca/pmix/pmix2x/pmix2x_server_south.c
@@ -4,7 +4,7 @@
  * Copyright (c) 2014-2017 Research Organization for Information Science
  *                         and Technology (RIST). All rights reserved.
  * Copyright (c) 2014-2016 Intel, Inc.  All rights reserved.
- * Copyright (c) 2014      Mellanox Technologies, Inc.
+ * Copyright (c) 2014-2017 Mellanox Technologies, Inc.
  *                         All rights reserved.
  * Copyright (c) 2016      Cisco Systems, Inc.  All rights reserved.
  * Copyright (c) 2017      Los Alamos National Security, LLC. All rights
@@ -109,8 +109,9 @@ int pmix2x_server_init(opal_pmix_server_module_t *module,
             asprintf(&dbgvalue, "PMIX_DEBUG=%d", dbg);
             putenv(dbgvalue);
         }
-        if (NULL != (evar = getenv("OPAL_PREFIX"))) {
-            opal_setenv("PMIX_PREFIX", evar, false, &environ);
+        if ((NULL != (evar = getenv("OPAL_PREFIX"))) && 
+            (NULL == getenv("PMIX_INSTALL_PREFIX"))) {
+            opal_setenv("PMIX_INSTALL_PREFIX", evar, false, &environ);
         }
     }
     ++opal_pmix_base.initialized;
diff --git a/orte/mca/plm/rsh/plm_rsh_module.c b/orte/mca/plm/rsh/plm_rsh_module.c
index 92ee33e21d..5b59e1b2f2 100644
--- a/orte/mca/plm/rsh/plm_rsh_module.c
+++ b/orte/mca/plm/rsh/plm_rsh_module.c
@@ -17,6 +17,7 @@
  * Copyright (c) 2014-2017 Intel, Inc.  All rights reserved.
  * Copyright (c) 2015-2017 Research Organization for Information Science
  *                         and Technology (RIST). All rights reserved.
+ * Copyright (c) 2017      Mellanox Technologies, Inc. All rights reserved.
  * $COPYRIGHT$
  *
  * Additional copyrights may follow
@@ -344,6 +345,7 @@ static int setup_launch(int *argcptr, char ***argvptr,
     bool found;
     char *lib_base=NULL, *bin_base=NULL;
     char *opal_prefix = getenv("OPAL_PREFIX");
+    char *pmix_prefix = getenv("PMIX_INSTALL_PREFIX");
     char* full_orted_cmd = NULL;
 
     /* Figure out the basenames for the libdir and bindir.  This
@@ -497,13 +499,16 @@ static int setup_launch(int *argcptr, char ***argvptr,
              * we have to insert the orted_prefix in the right place
              */
             (void)asprintf (&final_cmd,
-                            "%s%s%s PATH=%s%s$PATH ; export PATH ; "
+                            "%s%s%s %s%s%s PATH=%s%s$PATH ; export PATH ; "
                             "LD_LIBRARY_PATH=%s%s$LD_LIBRARY_PATH ; export LD_LIBRARY_PATH ; "
                             "DYLD_LIBRARY_PATH=%s%s$DYLD_LIBRARY_PATH ; export DYLD_LIBRARY_PATH ; "
                             "%s %s",
                             (opal_prefix != NULL ? "OPAL_PREFIX=" : " "),
                             (opal_prefix != NULL ? opal_prefix : " "),
                             (opal_prefix != NULL ? " ; export OPAL_PREFIX;" : " "),
+                            (pmix_prefix != NULL ? "PMIX_INSTALL_PREFIX=" : " "),
+                            (pmix_prefix != NULL ? pmix_prefix : " "),
+                            (pmix_prefix != NULL ? " ; export PMIX_INSTALL_PREFIX;" : " "),
                             (NULL != bin_base ? bin_base : " "),
                             (NULL != bin_base ? ":" : " "),
                             (NULL != lib_base ? lib_base : " "),