1 files changed, 6 insertions, 0 deletions
diff --git a/summain b/summain
index ac9d7c9..ff9e225 100755
--- a/summain
+++ b/summain
@@ -54,6 +54,12 @@ class Summain(cliapp.Application):
             pn = summainlib.SamePath()
         checksums = [x.upper() 
                      for x in self.settings['checksum'] or ['SHA1']]
+        o = summainlib.FilesystemObject('.', nn, pn, exclude, checksums)
+        for checksum in checksums:
+            try:
+                o[checksum]
+            except KeyError:
+                raise cliapp.AppException('Unknown checksum %s' % checksum)
         for root in args:
             for filename in self.files(root):
                 o = summainlib.FilesystemObject(filename, nn, pn, exclude,