diff --git a/LibCV/pywrapper.py b/LibCV/pywrapper.py
index 22aa7796..04e9492b 100644
--- a/LibCV/pywrapper.py
+++ b/LibCV/pywrapper.py
@@ -270,18 +270,21 @@ def check_sourceID(table_id):
     return(ierr)
 
 
-def check_filename(table_id, var_name, calendar, timeunits, infile):
+def check_filename(table_id, var_id, calendar, timeunits, infile):
     '''
       Validate filename with timestamp for current variable and file
 
       Usage:
-        cmip6_cv.check_filename(table_id, var_id)
+        cmip6_cv.check_filename(table_id, var_id, calendar, timeunits, infile)
       Where:
         table_id is the table id returned by load_table()
-        var_name is the variable name
+        var_id is the variable id returned by setup_variable()
+        calendar is the calendar type used by the file (ex. 360_day)
+        timeunits is the time unit type used by the file (ex. days since 1850-01-01)
+        infile is the name of the file
       Return 0 on success
     '''
-    ierr = _cmip6_cv.check_filename(table_id, var_name,
+    ierr = _cmip6_cv.check_filename(table_id, var_id,
                                     calendar, timeunits, infile)
     return(ierr)
 
diff --git a/Src/_controlvocabulary.c b/Src/_controlvocabulary.c
index afbfc3a2..d2129b80 100644
--- a/Src/_controlvocabulary.c
+++ b/Src/_controlvocabulary.c
@@ -17,16 +17,12 @@ static PyObject *PyCV_checkFilename(PyObject * self, PyObject * args)
     char *szInTimeCalendar;
     char *szInTimeUnits;
     char *infile;
-    int nTimeCalLen;
-    int nTimeUnitsLen;
-    int ninfile;
     int ierr;
 
     cmor_is_setup();
 
-    if (!PyArg_ParseTuple(args, "iis#s#s#", &ntable, &varid,
-                          &szInTimeCalendar, &nTimeCalLen,
-                          &szInTimeUnits, &nTimeUnitsLen, &infile, &ninfile)) {
+    if (!PyArg_ParseTuple(args, "iisss", &ntable, &varid,
+                          &szInTimeCalendar, &szInTimeUnits, &infile)) {
         return (Py_BuildValue("i", -1));
     }