diff --git a/src/ExprNode.cc b/src/ExprNode.cc
index 562d3c61cf1a1b1db64bc5ed4b5c3eccfbd0d627..fa86db50d98b2173ff0c891692e65931ad2b6724 100644
--- a/src/ExprNode.cc
+++ b/src/ExprNode.cc
@@ -5661,7 +5661,7 @@ BinaryOpNode::getPacAREC(int lhs_symb_id, int lhs_orig_symb_id,
                   vid = vn1->symb_id;
                   lag = vn1->lag;
                 }
-              if (pid > 0 && vid > 0)
+              if (pid >= 0 && vid >= 0)
                 {
                   int vidorig = vid;
                   while (datatree.symbol_table.isAuxiliaryVariable(vid))