diff --git a/testdata/parser/negative/29.txt b/testdata/parser/negative/29.txt
new file mode 100644
index 0000000000000000000000000000000000000000..9cc1cc21214d0c4045d2dd959c1fb5727e5bf4b6
--- /dev/null
+++ b/testdata/parser/negative/29.txt
@@ -0,0 +1,3 @@
+Parse error at 29.pdl:5:25: Unassignable expression
+    ++(x[0..5][2 - x[0]].length); // not assignable
+                        ^