diff --git a/crates/nu-parser/src/parser.rs b/crates/nu-parser/src/parser.rs
index b715af9a4..c809a3d6f 100644
--- a/crates/nu-parser/src/parser.rs
+++ b/crates/nu-parser/src/parser.rs
@@ -5995,7 +5995,7 @@ fn wrap_expr_with_collect(working_set: &mut StateWorkingSet, expr: &Expression)
     if let Some(decl_id) = working_set.find_decl(b"collect", &Type::Any) {
         let mut output = vec![];
 
-        let var_id = working_set.next_var_id();
+        let var_id = IN_VARIABLE_ID;
         let mut signature = Signature::new("");
         signature.required_positional.push(PositionalArg {
             var_id: Some(var_id),
diff --git a/src/tests/test_engine.rs b/src/tests/test_engine.rs
index dfed46dd7..8da2be1b2 100644
--- a/src/tests/test_engine.rs
+++ b/src/tests/test_engine.rs
@@ -365,3 +365,9 @@ fn better_operator_spans() -> TestResult {
 fn range_right_exclusive() -> TestResult {
     run_test(r#"[1, 4, 5, 8, 9] | range 1..<3 | math sum"#, "9")
 }
+
+/// Issue #7872
+#[test]
+fn assignment_to_in_var_no_panic() -> TestResult {
+    fail_test(r#"$in = 3"#, "needs to be a mutable variable")
+}