diff --git a/config/python.m4 b/config/python.m4
index b605212bea16a90fe1e8a705263602fb2c0a6de9..7f775e77d239c722b3cb3a5145c71057093a448b 100644
--- a/config/python.m4
+++ b/config/python.m4
@@ -31,6 +31,7 @@ else
 fi
 AC_MSG_CHECKING([Python configuration directory])
 python_majorversion=`${PYTHON} -c "import sys; print(sys.version[[0]])"`
+python_minorversion=`${PYTHON} -c "import sys; print(sys.version[[2]])"`
 python_version=`${PYTHON} -c "import sys; print(sys.version[[:3]])"`
 python_configdir=`${PYTHON} -c "import distutils.sysconfig; print(' '.join(filter(None,distutils.sysconfig.get_config_vars('LIBPL'))))"`
 AC_MSG_RESULT([$python_configdir])
diff --git a/configure b/configure
index 8468417f69b5011bcf98214915b1a917ee76489b..908109849e681861243d68ae27b88429dc7702a6 100755
--- a/configure
+++ b/configure
@@ -7588,6 +7588,7 @@ fi
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking Python configuration directory" >&5
 $as_echo_n "checking Python configuration directory... " >&6; }
 python_majorversion=`${PYTHON} -c "import sys; print(sys.version[0])"`
+python_minorversion=`${PYTHON} -c "import sys; print(sys.version[2])"`
 python_version=`${PYTHON} -c "import sys; print(sys.version[:3])"`
 python_configdir=`${PYTHON} -c "import distutils.sysconfig; print(' '.join(filter(None,distutils.sysconfig.get_config_vars('LIBPL'))))"`
 { $as_echo "$as_me:${as_lineno-$LINENO}: result: $python_configdir" >&5
@@ -7698,6 +7699,9 @@ $as_echo "${python_libspec} ${python_additional_libs}" >&6; }
 
 
 
+  if test "$python_majorversion" -lt 3 -a "$python_minorversion" -lt 4; then
+    as_fn_error $? "Python version $python_version is too old (version 2.4 or later is required)" "$LINENO" 5
+  fi
 fi
 
 if test "$cross_compiling" = yes && test -z "$with_system_tzdata"; then
diff --git a/configure.in b/configure.in
index 01b618c931ddd44e7d40460d86377ef0e27fb394..9e4fb0fa80a629e8fc63b5af4f11e5dca32b26dd 100644
--- a/configure.in
+++ b/configure.in
@@ -927,6 +927,9 @@ fi
 if test "$with_python" = yes; then
   PGAC_PATH_PYTHON
   PGAC_CHECK_PYTHON_EMBED_SETUP
+  if test "$python_majorversion" -lt 3 -a "$python_minorversion" -lt 4; then
+    AC_MSG_ERROR([Python version $python_version is too old (version 2.4 or later is required)])
+  fi
 fi
 
 if test "$cross_compiling" = yes && test -z "$with_system_tzdata"; then
diff --git a/contrib/hstore_plpython/expected/hstore_plpython.out b/contrib/hstore_plpython/expected/hstore_plpython.out
index b0025c04a81b409e8374f6b1f289899c7d912a75..df49cd5f373a284738d5de90b95babf40472bbc7 100644
--- a/contrib/hstore_plpython/expected/hstore_plpython.out
+++ b/contrib/hstore_plpython/expected/hstore_plpython.out
@@ -6,9 +6,7 @@ LANGUAGE plpythonu
 TRANSFORM FOR TYPE hstore
 AS $$
 assert isinstance(val, dict)
-i = list(val.items())
-i.sort()
-plpy.info(i)
+plpy.info(sorted(val.items()))
 return len(val)
 $$;
 SELECT test1('aa=>bb, cc=>NULL'::hstore);
@@ -24,9 +22,7 @@ LANGUAGE plpython2u
 TRANSFORM FOR TYPE hstore
 AS $$
 assert isinstance(val, dict)
-i = list(val.items())
-i.sort()
-plpy.info(i)
+plpy.info(sorted(val.items()))
 return len(val)
 $$;
 SELECT test1n('aa=>bb, cc=>NULL'::hstore);
diff --git a/contrib/hstore_plpython/sql/hstore_plpython.sql b/contrib/hstore_plpython/sql/hstore_plpython.sql
index d55bedaf50569ee834dffb0bf926155f68479486..911bbd67fede733702ecd2bd405549c69762bbdd 100644
--- a/contrib/hstore_plpython/sql/hstore_plpython.sql
+++ b/contrib/hstore_plpython/sql/hstore_plpython.sql
@@ -7,9 +7,7 @@ LANGUAGE plpythonu
 TRANSFORM FOR TYPE hstore
 AS $$
 assert isinstance(val, dict)
-i = list(val.items())
-i.sort()
-plpy.info(i)
+plpy.info(sorted(val.items()))
 return len(val)
 $$;
 
@@ -22,9 +20,7 @@ LANGUAGE plpython2u
 TRANSFORM FOR TYPE hstore
 AS $$
 assert isinstance(val, dict)
-i = list(val.items())
-i.sort()
-plpy.info(i)
+plpy.info(sorted(val.items()))
 return len(val)
 $$;
 
diff --git a/doc/src/sgml/installation.sgml b/doc/src/sgml/installation.sgml
index 182c801bd5271a3d41ad450a4ba73fc3847968a6..be0931326bc773da681655f9c2ae87fb601e19aa 100644
--- a/doc/src/sgml/installation.sgml
+++ b/doc/src/sgml/installation.sgml
@@ -193,11 +193,7 @@ su - postgres
       language, you need a <productname>Python</productname>
       installation with the header files and
       the <application>distutils</application> module.  The minimum
-      required version is <productname>Python</productname> 2.3.
-      (To work with function arguments of type <type>numeric</>, a 2.3.x
-      installation must include the separately-available <filename>cdecimal</>
-      module; note the <application>PL/Python</> regression tests
-      will not pass if that is missing.)
+      required version is <productname>Python</productname> 2.4.
       <productname>Python 3</productname> is supported if it's
       version 3.1 or later; but see
       <![%standalone-include[the <application>PL/Python</> documentation]]>
diff --git a/src/pl/plpython/expected/plpython_ereport.out b/src/pl/plpython/expected/plpython_ereport.out
index 13bd0ab3352dbc7a625373824dd6b47f6eaad99c..1dafd94c7214b521cef988aa8a9f4176413e08ef 100644
--- a/src/pl/plpython/expected/plpython_ereport.out
+++ b/src/pl/plpython/expected/plpython_ereport.out
@@ -94,26 +94,22 @@ kwargs = {
     "column_name": _column_name, "datatype_name": _datatype_name,
     "constraint_name": _constraint_name
 }
-# ignore None values - should work on Python2.3
-dict = {}
-for k in kwargs:
-    if kwargs[k] is not None:
-        dict[k] = kwargs[k]
-plpy.error(**dict)
+# ignore None values
+plpy.error(**dict((k, v) for k, v in iter(kwargs.items()) if v))
 $$ LANGUAGE plpythonu;
 SELECT raise_exception('hello', 'world');
 ERROR:  plpy.Error: hello
 DETAIL:  world
 CONTEXT:  Traceback (most recent call last):
-  PL/Python function "raise_exception", line 13, in <module>
-    plpy.error(**dict)
+  PL/Python function "raise_exception", line 9, in <module>
+    plpy.error(**dict((k, v) for k, v in iter(kwargs.items()) if v))
 PL/Python function "raise_exception"
 SELECT raise_exception('message text', 'detail text', _sqlstate => 'YY333');
 ERROR:  plpy.Error: message text
 DETAIL:  detail text
 CONTEXT:  Traceback (most recent call last):
-  PL/Python function "raise_exception", line 13, in <module>
-    plpy.error(**dict)
+  PL/Python function "raise_exception", line 9, in <module>
+    plpy.error(**dict((k, v) for k, v in iter(kwargs.items()) if v))
 PL/Python function "raise_exception"
 SELECT raise_exception(_message => 'message text',
                        _detail => 'detail text',
@@ -128,8 +124,8 @@ ERROR:  plpy.Error: message text
 DETAIL:  detail text
 HINT:  hint text
 CONTEXT:  Traceback (most recent call last):
-  PL/Python function "raise_exception", line 13, in <module>
-    plpy.error(**dict)
+  PL/Python function "raise_exception", line 9, in <module>
+    plpy.error(**dict((k, v) for k, v in iter(kwargs.items()) if v))
 PL/Python function "raise_exception"
 SELECT raise_exception(_message => 'message text',
                        _hint => 'hint text',
@@ -139,8 +135,8 @@ SELECT raise_exception(_message => 'message text',
 ERROR:  plpy.Error: message text
 HINT:  hint text
 CONTEXT:  Traceback (most recent call last):
-  PL/Python function "raise_exception", line 13, in <module>
-    plpy.error(**dict)
+  PL/Python function "raise_exception", line 9, in <module>
+    plpy.error(**dict((k, v) for k, v in iter(kwargs.items()) if v))
 PL/Python function "raise_exception"
 DO $$
 DECLARE
diff --git a/src/pl/plpython/plpy_typeio.c b/src/pl/plpython/plpy_typeio.c
index b9c6d64baafd327824ef59e82d8068adbaf747ba..06743e46ed5a5ffdb4ca5103b490152f457dd3ba 100644
--- a/src/pl/plpython/plpy_typeio.c
+++ b/src/pl/plpython/plpy_typeio.c
@@ -521,15 +521,9 @@ PLy_input_datum_func2(PLyDatumToOb *arg, MemoryContext arg_mcxt, Oid typeOid, He
 static PyObject *
 PLyBool_FromBool(PLyDatumToOb *arg, Datum d)
 {
-	/*
-	 * We would like to use Py_RETURN_TRUE and Py_RETURN_FALSE here for
-	 * generating SQL from trigger functions, but those are only supported in
-	 * Python >= 2.4, and we support older versions.
-	 * http://docs.python.org/api/boolObjects.html
-	 */
 	if (DatumGetBool(d))
-		return PyBool_FromLong(1);
-	return PyBool_FromLong(0);
+		Py_RETURN_TRUE;
+	Py_RETURN_FALSE;
 }
 
 static PyObject *
diff --git a/src/pl/plpython/sql/plpython_ereport.sql b/src/pl/plpython/sql/plpython_ereport.sql
index 2612e933876760cbb1f6ce251d7879960ee2c5d7..889293d33c93d7c0dbb3a492226fb70b6b7b2984 100644
--- a/src/pl/plpython/sql/plpython_ereport.sql
+++ b/src/pl/plpython/sql/plpython_ereport.sql
@@ -55,12 +55,8 @@ kwargs = {
     "column_name": _column_name, "datatype_name": _datatype_name,
     "constraint_name": _constraint_name
 }
-# ignore None values - should work on Python2.3
-dict = {}
-for k in kwargs:
-    if kwargs[k] is not None:
-        dict[k] = kwargs[k]
-plpy.error(**dict)
+# ignore None values
+plpy.error(**dict((k, v) for k, v in iter(kwargs.items()) if v))
 $$ LANGUAGE plpythonu;
 
 SELECT raise_exception('hello', 'world');