diff --git a/startup/20-area-detectors.py b/startup/20-area-detectors.py
index a9e12a5..437db1f 100644
--- a/startup/20-area-detectors.py
+++ b/startup/20-area-detectors.py
@@ -44,7 +44,7 @@ def describe(self):
             raise RuntimeError("SHould never be here")
         
         cam_dtype = self.parent.cam.data_type.get(as_string=True)
-        type_map = {'UInt8': '|u1', 'UInt16': '<u2', 'Float32':'<f4', "Float32":'<f8'}
+        type_map = {'UInt8': '|u1', 'UInt16': '<u2', 'Float32':'<f4', "Float64":'<f8'}
         if cam_dtype in type_map:
             ret[key].setdefault('dtype_str', type_map[cam_dtype])