/* struct module */
-PyObject *structmodule = NULL;
-PyObject *Struct = NULL;
-PyObject *calcsize = NULL;
+static PyObject *structmodule = NULL;
+static PyObject *Struct = NULL;
+static PyObject *calcsize = NULL;
/* cache simple format string */
static const char *simple_fmt = "B";
-PyObject *simple_format = NULL;
+static PyObject *simple_format = NULL;
#define SIMPLE_FORMAT(fmt) (fmt == NULL || strcmp(fmt, "B") == 0)
#define FIX_FORMAT(fmt) (fmt == NULL ? "B" : fmt)