diff --git a/config/ompi_setup_prrte.m4 b/config/ompi_setup_prrte.m4
index 1d9348dbe5..56bb39fbf6 100644
--- a/config/ompi_setup_prrte.m4
+++ b/config/ompi_setup_prrte.m4
@@ -148,7 +148,7 @@ dnl        [internal_prrte_args="$internal_prrte_args --with-platform=$with_prrt
             [[--with-libevent=internal], [--with-hwloc=internal],
              [--with-libevent=external], [--with-hwloc=external],
              [--with-pmix=internal], [--with-pmix=external],
-             [--with-platform=.*]],
+             [--with-platform=[[^ 	]]*]],
             [], [internal_prrte_happy="no"])
     OPAL_3RDPARTY_DIST_SUBDIRS="$OPAL_3RDPARTY_DIST_SUBDIRS prrte"
 
diff --git a/config/opal_config_pmix.m4 b/config/opal_config_pmix.m4
index 61d2414f59..e25f2ca564 100644
--- a/config/opal_config_pmix.m4
+++ b/config/opal_config_pmix.m4
@@ -91,7 +91,7 @@ AC_DEFUN([OPAL_CONFIG_PMIX], [
          PAC_CONFIG_SUBDIR_ARGS([3rd-party/openpmix], [$internal_pmix_args],
                            [[--with-libevent=internal], [--with-hwloc=internal],
                             [--with-libevent=external], [--with-hwloc=external],
-                            [--with-pmix=.*], [--with-platform=.*]],
+                            [--with-pmix=[[^ 	]]*], [--with-platform=[[^ 	]]*]],
                            [internal_pmix_happy=1])
          OPAL_3RDPARTY_DIST_SUBDIRS="$OPAL_3RDPARTY_DIST_SUBDIRS openpmix"])