diff --git a/Python/ceval.c b/Python/ceval.c
index defd002..3ea9059 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -742,7 +742,7 @@
 	consts = co->co_consts;
 	fastlocals = f->f_localsplus;
 	freevars = f->f_localsplus + co->co_nlocals;
-	first_instr = (unsigned char*) PyString_AS_STRING(co->co_code);
+	first_instr = (unsigned char*) PyBytes_AS_STRING(co->co_code);
 	/* An explanation is in order for the next line.
 
 	   f->f_lasti now refers to the index of the last instruction