diff --git a/loopy/frontend/fortran/expression.py b/loopy/frontend/fortran/expression.py
index d4e71893511c9a426aa6d9d966ce3a0c7444d21d..ea724278f086befe7d93cdd076aca9d5955063b2 100644
--- a/loopy/frontend/fortran/expression.py
+++ b/loopy/frontend/fortran/expression.py
@@ -25,6 +25,7 @@ THE SOFTWARE.
 from pymbolic.parser import Parser as ExpressionParserBase
 from loopy.frontend.fortran.diagnostic import TranslationError
 
+from six.moves import intern
 import numpy as np
 
 import pytools.lex