--- _warnings.c	2009-07-17 08:33:04.000000000 +0200
+++ _warnings.c	2010-05-25 17:29:40.000000000 +0200
@@ -531,6 +531,16 @@ setup_context(Py_ssize_t stack_level, Py
             Py_INCREF(*filename);
     }
     else {
+				PyCodeObject *f_code = (PyCodeObject*)f->f_code;
+				if(f_code!=NULL) {
+					PyObject *co_filename = f_code->co_filename;
+					if(co_filename!=NULL) {
+						*filename = PyObject_Str(co_filename);
+						//*filename already INCREF'ed
+						return 1;
+					}
+				}
+				
         const char *module_str = PyString_AsString(*module);
         if (module_str && strcmp(module_str, "__main__") == 0) {
             PyObject *argv = PySys_GetObject("argv");