diff --git a/docs/mca.rst b/docs/mca.rst
index ff640817806..3ab33d46fe0 100644
--- a/docs/mca.rst
+++ b/docs/mca.rst
@@ -252,13 +252,13 @@ shells):
              When setting PMIx- and PRRTE-specific MCA parameters via
              environment variables, use a different prefix:
 
-             +----------+----------------+
-             | Open MPI | ``OMPI_MCA_``  |
-             +----------+----------------+
-             | PMIx     | ``PMIX_MCA_``  |
-             +----------+----------------+
-             | PRRTE    | ``PRRTE_MCA_`` |
-             +----------+----------------+
+             +----------+-----------------------------------+
+             | Open MPI | ``OMPI_MCA_``                     |
+             +----------+-----------------------------------+
+             | PMIx     | ``PMIX_MCA_``                     |
+             +----------+-----------------------------------+
+             | PRRTE    | ``PRTE_MCA_`` (with a single "R") |
+             +----------+-----------------------------------+
 
 Tuning MCA parameter files
 ^^^^^^^^^^^^^^^^^^^^^^^^^^