diff --git a/crates/perry-hir/src/lower_decl/class_decl.rs b/crates/perry-hir/src/lower_decl/class_decl.rs
index cc1fea5403..30edc4e982 100644
--- a/crates/perry-hir/src/lower_decl/class_decl.rs
+++ b/crates/perry-hir/src/lower_decl/class_decl.rs
@@ -413,6 +413,22 @@ pub fn lower_class_decl(
                 // class) tag for the runtime shim).
                 (None, Some(parent_name), native_parent, None)
             } else {
+                // #5437 (Next.js NodeNextRequest cross-module heritage): a
+                // minified bundle declares the SAME class name in several
+                // turbopack factory closures (`class f{...}` appears 3× in one
+                // chunk). Phase-1.5 disambiguates the duplicate sibling by
+                // renaming it (`f` -> `f$0`) in this body's scope, and the
+                // class registers under that unique name — but the child's
+                // `extends f` was binding to the RAW name, which `lookup_class`
+                // resolves to the FIRST (wrong) `f`. The parent-chain walk then
+                // pulls the wrong class's fields into `packed_keys`, dropping
+                // the real parent's `method`/`url`/`body` (NodeNextRequest's
+                // `e.url` read undefined -> `Invalid URL` 500 on dynamic page
+                // routes). Resolve the parent name through the active
+                // scope-local renames so heritage binds to the same disambiguated
+                // class the parent decl registered under. Identity for
+                // non-colliding names, so unaffected classes keep their parent.
+                let parent_name = ctx.resolve_class_name(&parent_name);
                 let parent_cid = ctx.lookup_class(&parent_name);
                 if parent_cid.is_none() {
                     // Issue #711 part 2: the Ident doesn't resolve to
@@ -1392,6 +1408,11 @@ pub fn lower_class_from_ast(
             if native_parent.is_some() {
                 (None, Some(parent_name), native_parent, None)
             } else {
+                // #5437: resolve the parent through active scope-local class
+                // renames so a class EXPRESSION extending a disambiguated
+                // same-named sibling (`f` -> `f$0`) binds to the right class.
+                // See the matching fix in `lower_class_decl` above.
+                let parent_name = ctx.resolve_class_name(&parent_name);
                 let parent_cid = ctx.lookup_class(&parent_name);
                 if parent_cid.is_none() {
                     // Issue #711 part 2: see the parallel arm in
diff --git a/crates/perry/tests/issue_5437_heritage_colliding_class_name_fields.rs b/crates/perry/tests/issue_5437_heritage_colliding_class_name_fields.rs
new file mode 100644
index 0000000000..8667ba7277
--- /dev/null
+++ b/crates/perry/tests/issue_5437_heritage_colliding_class_name_fields.rs
@@ -0,0 +1,107 @@
+//! Regression test for #5437 (Next.js Wall #7b, dynamic PAGE routes 500
+//! `Error: Invalid URL`): a minified bundle declares the SAME class name in
+//! several turbopack factory closures (Next.js's chunk has `class f{...}`
+//! three times). When a capturing child `class h extends f` is declared in a
+//! LATER factory, Phase-1.5 disambiguates that factory's `f` by renaming it
+//! (`f` -> `f$0`) so it registers as a distinct class — but the child's
+//! `extends f` was binding to the RAW name, which resolves to the FIRST
+//! (wrong) `f`. The codegen parent-chain walk then pulls the wrong class's
+//! fields into `packed_keys`, dropping the real parent's `method`/`url`/`body`.
+//!
+//! Concretely, Next.js's `NodeNextRequest (h) extends BaseNextRequest (f)`
+//! lost `f`'s `method`/`url`/`body` fields, so `new NodeNextRequest(req).url`
+//! read `undefined` and the app-page render's `if (!e.url) throw "Invalid URL"`
+//! 500'd every dynamic page route (`/posts/[id]`, `/fetcher`).
+//!
+//! Fix: resolve the Ident super-class name through the active scope-local class
+//! renames (`resolve_class_name`) in both `lower_class_decl` and
+//! `lower_class_from_ast`, so heritage binds to the SAME disambiguated class the
+//! parent decl registered under. Identity for non-colliding names.
+
+use std::path::PathBuf;
+use std::process::Command;
+
+fn perry_bin() -> PathBuf {
+    PathBuf::from(env!("CARGO_BIN_EXE_perry"))
+}
+
+#[test]
+fn heritage_binds_to_disambiguated_same_named_parent_keeping_its_fields() {
+    let dir = tempfile::tempdir().expect("tempdir");
+    let entry = dir.path().join("main.js");
+    let output = dir.path().join("main_bin");
+    std::fs::write(
+        &entry,
+        r#"
+"use strict";
+const MODS = { 85729: { NEXT_REQUEST_META: Symbol("next.req.meta") } };
+const a = { i: (id) => MODS[id] };
+
+// Factory A: a DECOY `class f` with NO method/url/body, declared FIRST so a
+// naive by-name `extends f` resolution picks this one.
+const modA = ((a) => {
+  class f { constructor() { this.decoyA = 1; this.decoyB = 2; } }
+  class q extends f { constructor() { super(); this.qf = 9; } }
+  return { Q: q };
+})(a);
+
+// Factory B: the REAL base `class f` (method/url/body) + a capturing child
+// `class h extends f`. Phase-1.5 renames this `f` to a unique name; the child's
+// `extends f` must bind to THAT renamed class, not factory A's decoy.
+const modB = ((a) => {
+  var c, d = a.i(85729);
+  class f { constructor(m, u, b) { this.method = m; this.url = u; this.body = b; } }
+  class h extends f {
+    static #a = (c = d.NEXT_REQUEST_META);
+    constructor(req) {
+      super(req.method.toUpperCase(), req.url, req);
+      this._req = req;
+      this.headers = req.headers;
+      this.fetchMetrics = req.fetchMetrics;
+      this[c] = req[d.NEXT_REQUEST_META] || {};
+      this.streaming = false;
+    }
+  }
+  return { NodeNextRequest: h };
+})(a);
+
+const make = (b) => new modB.NodeNextRequest(b);
+const req = { method: "get", url: "/posts/123", headers: { a: 1 }, fetchMetrics: null };
+const n = make(req);
+console.log("url=" + n.url);
+console.log("method=" + n.method);
+"#,
+    )
+    .expect("write entry");
+
+    let compile = Command::new(perry_bin())
+        .current_dir(dir.path())
+        .arg("compile")
+        .arg(&entry)
+        .arg("-o")
+        .arg(&output)
+        .output()
+        .expect("run perry compile");
+    assert!(
+        compile.status.success(),
+        "perry compile failed\nstdout:\n{}\nstderr:\n{}",
+        String::from_utf8_lossy(&compile.stdout),
+        String::from_utf8_lossy(&compile.stderr)
+    );
+
+    let run = Command::new(&output).output().expect("run compiled binary");
+    assert!(
+        run.status.success(),
+        "compiled binary failed\nstatus: {:?}\nstdout:\n{}\nstderr:\n{}",
+        run.status,
+        String::from_utf8_lossy(&run.stdout),
+        String::from_utf8_lossy(&run.stderr)
+    );
+    let stdout = String::from_utf8_lossy(&run.stdout);
+    assert_eq!(
+        stdout, "url=/posts/123\nmethod=GET\n",
+        "a capturing child extending a disambiguated same-named parent must \
+         inherit THAT parent's ctor-assigned fields (method/url/body), not a \
+         decoy same-named class's fields — #5437 NodeNextRequest Wall #7b"
+    );
+}