diff --git a/lib/spack/spack/util/environment.py b/lib/spack/spack/util/environment.py
index 1acbb64790f..8069f514319 100644
--- a/lib/spack/spack/util/environment.py
+++ b/lib/spack/spack/util/environment.py
@@ -604,7 +604,8 @@ def from_sourcing_file(filename, *arguments, **kwargs):
 
         # Compute the environments before and after sourcing
         before = sanitize(
-            dict(os.environ), blacklist=blacklist, whitelist=whitelist
+            environment_after_sourcing_files(os.devnull, **kwargs),
+            blacklist=blacklist, whitelist=whitelist
         )
         file_and_args = (filename,) + arguments
         after = sanitize(