diff --git a/lib/spack/llnl/util/filesystem.py b/lib/spack/llnl/util/filesystem.py
index 1d7b9ff7a38..5ed4d9249ad 100644
--- a/lib/spack/llnl/util/filesystem.py
+++ b/lib/spack/llnl/util/filesystem.py
@@ -136,7 +136,7 @@ def groupid_to_group(x):
             raise
 
         finally:
-            if not backup:
+            if not backup and os.path.exists(backup_filename):
                 os.remove(backup_filename)