diff --git a/lib/spack/spack/util/environment.py b/lib/spack/spack/util/environment.py
index 073f60334e1..075d7e88eae 100644
--- a/lib/spack/spack/util/environment.py
+++ b/lib/spack/spack/util/environment.py
@@ -989,7 +989,7 @@ def _source_single_file(file_and_args, environment):
         python_cmd = python_cmd.name if python_cmd else sys.executable
 
         dump_cmd = 'import os, json; print(json.dumps(dict(os.environ)))'
-        dump_environment = python_cmd + ' -c "{0}"'.format(dump_cmd)
+        dump_environment = python_cmd + ' -E -c "{0}"'.format(dump_cmd)
 
         # Try to source the file
         source_file_arguments = ' '.join([
diff --git a/lib/spack/spack/util/module_cmd.py b/lib/spack/spack/util/module_cmd.py
index d8c3ec8d148..b3c3db9b93c 100644
--- a/lib/spack/spack/util/module_cmd.py
+++ b/lib/spack/spack/util/module_cmd.py
@@ -47,7 +47,7 @@ def module(*args):
         module_cmd += 'LD_LIBRARY_PATH="$SPACK_LD_LIBRARY_PATH" '
 
         # Execute the python command
-        module_cmd += '%s -c "%s";' % (sys.executable, py_cmd)
+        module_cmd += '%s -E -c "%s";' % (sys.executable, py_cmd)
 
         # If LD_LIBRARY_PATH was set after `module`, dump the old value because
         # we have since corrupted it to ensure python would run.