diff --git a/lib/spack/spack/stage.py b/lib/spack/spack/stage.py
index 5d8b09fa9e..985043c103 100644
--- a/lib/spack/spack/stage.py
+++ b/lib/spack/spack/stage.py
@@ -246,7 +246,7 @@ def fetch(self, mirror_only=False):
                 self.fetcher = fetcher
                 self.fetcher.fetch()
                 break
-            except spack.error.SpackError, e:
+            except spack.error.SpackError as e:
                 tty.msg("Fetching from %s failed." % fetcher)
                 tty.debug(e)
                 continue