diff --git a/src/python/amrclaw/data.py b/src/python/amrclaw/data.py
index cad6863a..47c1f049 100755
--- a/src/python/amrclaw/data.py
+++ b/src/python/amrclaw/data.py
@@ -435,8 +435,8 @@ def write(self, num_eqn, num_aux, out_file='gauges.data',
             self.expand_gauge_format_option(key)
 
         # File format
-        self._out_file.write("# File format (1=ascii, 2=binary)\n")
-        format_map = {'ascii':1, 'binary': 2}
+        self._out_file.write("# File format (1=ascii, 2=binary64, 3=binary32)\n")
+        format_map = {'ascii':1, 'binary':2, 'binary64':2, 'binary32':3}
         for gauge_num in self.gauge_numbers:
             try:
                 file_format = format_map[self.file_format[gauge_num].lower()]