diff --git a/src/DataFilter.y b/src/DataFilter.y
index 697724000..4212a01d0 100644
--- a/src/DataFilter.y
+++ b/src/DataFilter.y
@@ -88,6 +88,11 @@ lexpr : expr lop expr             { $$ = new Leaf();
                                       $$->lvalue.l = $1;
                                       $$->op = $2;
                                       $$->rvalue.l = $3; }
+        | lexpr lop lexpr             { $$ = new Leaf();
+                                      $$->type = Leaf::Logical;
+                                      $$->lvalue.l = $1;
+                                      $$->op = $2;
+                                      $$->rvalue.l = $3; }
         | '(' expr ')'               { $$ = new Leaf();
                                       $$->type = Leaf::Logical;
                                       $$->lvalue.l = $2;