diff --git a/src/pl/plpython/expected/plpython_test.out b/src/pl/plpython/expected/plpython_test.out
index 7b76faf..f8270a7 100644
*** a/src/pl/plpython/expected/plpython_test.out
--- b/src/pl/plpython/expected/plpython_test.out
*************** select stupidn();
*** 16,23 ****
   zarkon
  (1 row)
  
! -- test multiple arguments
! CREATE FUNCTION argument_test_one(u users, a1 text, a2 text) RETURNS text
  	AS
  'keys = list(u.keys())
  keys.sort()
--- 16,23 ----
   zarkon
  (1 row)
  
! -- test multiple arguments and odd characters in function name
! CREATE FUNCTION "Argument test #1"(u users, a1 text, a2 text) RETURNS text
  	AS
  'keys = list(u.keys())
  keys.sort()
*************** for key in keys:
*** 27,34 ****
  words = a1 + " " + a2 + " => {" + ", ".join(out) + "}"
  return words'
  	LANGUAGE plpythonu;
! select argument_test_one(users, fname, lname) from users where lname = 'doe' order by 1;
!                            argument_test_one                           
  -----------------------------------------------------------------------
   jane doe => {fname: jane, lname: doe, userid: 1, username: j_doe}
   john doe => {fname: john, lname: doe, userid: 2, username: johnd}
--- 27,34 ----
  words = a1 + " " + a2 + " => {" + ", ".join(out) + "}"
  return words'
  	LANGUAGE plpythonu;
! select "Argument test #1"(users, fname, lname) from users where lname = 'doe' order by 1;
!                            Argument test #1                            
  -----------------------------------------------------------------------
   jane doe => {fname: jane, lname: doe, userid: 1, username: j_doe}
   john doe => {fname: john, lname: doe, userid: 2, username: johnd}
diff --git a/src/pl/plpython/plpy_procedure.c b/src/pl/plpython/plpy_procedure.c
index e1f5620..a0d0792 100644
*** a/src/pl/plpython/plpy_procedure.c
--- b/src/pl/plpython/plpy_procedure.c
*************** PLy_procedure_create(HeapTuple procTup, 
*** 146,151 ****
--- 146,152 ----
  	MemoryContext cxt;
  	MemoryContext oldcxt;
  	int			rv;
+ 	char	   *ptr;
  
  	procStruct = (Form_pg_proc) GETSTRUCT(procTup);
  	rv = snprintf(procName, sizeof(procName),
*************** PLy_procedure_create(HeapTuple procTup, 
*** 155,160 ****
--- 156,170 ----
  	if (rv >= sizeof(procName) || rv < 0)
  		elog(ERROR, "procedure name would overrun buffer");
  
+ 	/* Replace any not-legal-in-Python-names characters with '_' */
+ 	for (ptr = procName; *ptr; ptr++)
+ 	{
+ 		if (!((*ptr >= 'A' && *ptr <= 'Z') ||
+ 			  (*ptr >= 'a' && *ptr <= 'z') ||
+ 			  (*ptr >= '0' && *ptr <= '9')))
+ 			*ptr = '_';
+ 	}
+ 
  	cxt = AllocSetContextCreate(TopMemoryContext,
  								procName,
  								ALLOCSET_DEFAULT_MINSIZE,
diff --git a/src/pl/plpython/sql/plpython_test.sql b/src/pl/plpython/sql/plpython_test.sql
index c8d5ef5..3a76104 100644
*** a/src/pl/plpython/sql/plpython_test.sql
--- b/src/pl/plpython/sql/plpython_test.sql
*************** CREATE FUNCTION stupidn() RETURNS text A
*** 11,18 ****
  
  select stupidn();
  
! -- test multiple arguments
! CREATE FUNCTION argument_test_one(u users, a1 text, a2 text) RETURNS text
  	AS
  'keys = list(u.keys())
  keys.sort()
--- 11,18 ----
  
  select stupidn();
  
! -- test multiple arguments and odd characters in function name
! CREATE FUNCTION "Argument test #1"(u users, a1 text, a2 text) RETURNS text
  	AS
  'keys = list(u.keys())
  keys.sort()
*************** words = a1 + " " + a2 + " => {" + ", ".j
*** 23,29 ****
  return words'
  	LANGUAGE plpythonu;
  
! select argument_test_one(users, fname, lname) from users where lname = 'doe' order by 1;
  
  
  -- check module contents
--- 23,29 ----
  return words'
  	LANGUAGE plpythonu;
  
! select "Argument test #1"(users, fname, lname) from users where lname = 'doe' order by 1;
  
  
  -- check module contents