diff --git a/testdata/ruby/dbLayoutQuery.rb b/testdata/ruby/dbLayoutQuery.rb
index 3501115fe..dd10102b0 100644
--- a/testdata/ruby/dbLayoutQuery.rb
+++ b/testdata/ruby/dbLayoutQuery.rb
@@ -77,6 +77,7 @@ class DBLayoutQuery_TestClass < TestBase
     ctx = RBA::ExpressionContext::new
     ctx.var("suffix", "!")
     ctx.var("all", [])
+    ctx.var("nonmod", "")
 
     q = RBA::LayoutQuery::new("select cell.name + suffix from *")
     res = []
@@ -88,10 +89,13 @@ class DBLayoutQuery_TestClass < TestBase
     assert_equal(res[0], "[\"TOPTOP!\"]")
     assert_equal(res[1], "[\"TOP!\"]")
 
-    q = RBA::LayoutQuery::new("with * do all.push(cell.name)")
+    q = RBA::LayoutQuery::new("with * do var nonmod = cell.name; all.push(nonmod)")
     q.execute(ly, ctx)
 
     assert_equal(ctx.eval("all").join(","), "TOPTOP,TOP")
+    # not modified, because we used "var nonmod" in the query which
+    # creates a local variable:
+    assert_equal(ctx.eval("nonmod"), "")
 
   end