diff --git a/da/tools/io4.py b/da/tools/io4.py
index 56f16fc0e3ff107f7db3654f8330e860af2c7779..ebd8e419ff54ea61d14312fab02bc8dbedf58408 100755
--- a/da/tools/io4.py
+++ b/da/tools/io4.py
@@ -361,7 +361,7 @@ class CT_HDF(hdf.SD):
             #print 'Reading from file'
 	    try:
             	super(CT_HDF,self).__init__(filename) 
-	    except HDF4Error: 
+	    except hdf.HDF4Error: 
                 msg = 'Requested file not found for opening: %s'%filename ; logging.error(msg)
                 msg = "Exiting" ; logging.info(msg)
                 sys.exit(2)