diff --git a/crates/script/src/prelude.js b/crates/script/src/prelude.js
index 76155b82..f707daf7 100644
--- a/crates/script/src/prelude.js
+++ b/crates/script/src/prelude.js
@@ -1342,7 +1342,18 @@ Item.prototype = {
   get parentFolder() { return __item(this.__info().parent); },
   set parentFolder(f) { __call("project.move", { items: [this.__id], folder: f && f.__id ? f.__id : null }); },
   get selected() { return this.__info().selected; },
-  set selected(v) { if (v) __call("project.select", { items: [this.__id], add: true }); },
+  set selected(v) {
+    var selection = __get("project").selection;
+    var selected = selection.indexOf(this.__id) !== -1;
+    if (!!v === selected) return;
+    if (v) {
+      __call("project.select", { items: [this.__id], add: true });
+    } else {
+      var id = this.__id;
+      // Replace just this item, preserving the other Project panel selections and their order.
+      __call("project.select", { items: selection.filter(function (item) { return item !== id; }) });
+    }
+  },
   get usedIn() { return this.__info().usedIn.map(function (c) { return new CompItem(c); }); },
   remove: function () { __call("project.delete", { items: [this.__id] }); },
 };
diff --git a/crates/script/src/tests.rs b/crates/script/src/tests.rs
index 60f59ca3..45be6225 100644
--- a/crates/script/src/tests.rs
+++ b/crates/script/src/tests.rs
@@ -564,3 +564,31 @@ fn text_document_baseline_flags_reflect_pending_edits_and_applied_value() {
         ])
     );
 }
+
+#[test]
+fn setting_item_selected_false_preserves_other_project_items() {
+    let mut s = session();
+    let o = ok(
+        &mut s,
+        r#"
+        var target = app.project.items.addFolder("Target");
+        var keep = app.project.items.addFolder("Keep");
+        app.run("project.select", {items: []});
+        keep.selected = true;
+        target.selected = true;
+        var states = [[target.selected, keep.selected]];
+        target.selected = false;
+        states.push([target.selected, keep.selected]);
+        target.selected = false; // idempotent: never remove Keep
+        states.push([target.selected, keep.selected]);
+        target.selected = true;
+        states.push([target.selected, keep.selected]);
+        app.project.selection.map(function (item) { return item.name; }).join(",")
+          + "|" + JSON.stringify(states);
+        "#,
+    );
+    assert_eq!(
+        o.result,
+        json!("Keep,Target|[[true,true],[false,true],[false,true],[true,true]]")
+    );
+}