diff --git a/config/python.m4 b/config/python.m4
index d41aeb2876a..bfcba30262c 100644
--- a/config/python.m4
+++ b/config/python.m4
@@ -9,14 +9,12 @@
 # Look for Python and set the output variable 'PYTHON' if found,
 # fail otherwise.
 #
-# As the Python 3 transition happens and PEP 394 isn't updated, we
-# need to cater to systems that don't have unversioned "python" by
-# default.  Some systems ship with "python3" by default and perhaps
-# have "python" in an optional package.  Some systems only have
-# "python2" and "python3", in which case it's reasonable to prefer the
-# newer version.
+# Since we are transitioning to supporting only Python 3.x,
+# prefer python3 to plain python.  If the latter exists at all,
+# it very possibly points to python2, which we don't want to
+# select unless it's the only choice.
 AC_DEFUN([PGAC_PATH_PYTHON],
-[PGAC_PATH_PROGS(PYTHON, [python python3 python2])
+[PGAC_PATH_PROGS(PYTHON, [python3 python python2])
 AC_ARG_VAR(PYTHON, [Python program])dnl
 if test x"$PYTHON" = x""; then
   AC_MSG_ERROR([Python not found])
diff --git a/configure b/configure
index 3f2aea0d7de..fb4064afa54 100755
--- a/configure
+++ b/configure
@@ -10279,7 +10279,7 @@ fi
 
 if test "$with_python" = yes; then
   if test -z "$PYTHON"; then
-  for ac_prog in python python3 python2
+  for ac_prog in python3 python python2
 do
   # Extract the first word of "$ac_prog", so it can be a program name with args.
 set dummy $ac_prog; ac_word=$2
diff --git a/doc/src/sgml/installation.sgml b/doc/src/sgml/installation.sgml
index d38f9bc9160..a5cf0d2657a 100644
--- a/doc/src/sgml/installation.sgml
+++ b/doc/src/sgml/installation.sgml
@@ -1875,7 +1875,7 @@ build-postgresql:
          language becomes available.  See
          <xref linkend="plpython-python23"/>
          for more information.  If this is not set, the following are probed
-         in this order: <literal>python python3 python2</literal>.
+         in this order: <literal>python3 python python2</literal>.
         </para>
        </listitem>
       </varlistentry>