--- cfitsio3-3.210.orig/buffers.c
+++ cfitsio3-3.210/buffers.c
@@ -765,6 +765,14 @@
     return(*status);
 }
 /*--------------------------------------------------------------------------*/
+int fits_get_num_files(void)
+/*
+  Returns the number of FITS files currently opened in CFITSIO
+*/
+{
+    return -1;
+}
+/*--------------------------------------------------------------------------*/
 int ffgtbb(fitsfile *fptr,        /* I - FITS file pointer                 */
            LONGLONG firstrow,         /* I - starting row (1 = first row)      */
            LONGLONG firstchar,        /* I - starting byte in row (1=first)    */