diff -r 2eefecd93d0f pypy/module/_cffi_backend/test/test_re_python.py
--- a/pypy/module/_cffi_backend/test/test_re_python.py  Mon Oct 16 08:36:02 2023 +0200
+++ b/pypy/module/_cffi_backend/test/test_re_python.py  Sun Dec 29 18:54:07 2024 +0100
@@ -32,6 +32,7 @@
         struct foo_s;
         typedef struct bar_s { int x; signed char a[]; } bar_t;
         enum foo_e { AA, BB, CC };
+        struct B { struct C* c; }; struct C { struct B b; };

         void init_test_re_python(void) { }      /* windows hack */
         void PyInit__test_re_python(void) { }   /* windows hack */
@@ -270,3 +271,15 @@

         err = lib1.dlclose(handle)
         assert err == 0
+
+    def test_rec_structs_1(self):
+        self.fix_path()
+        from re_python_pysrc import ffi
+        sz = ffi.sizeof("struct B")
+        assert sz == ffi.sizeof("int *")
+
+    def test_rec_structs_2(self):
+        self.fix_path()
+        from re_python_pysrc import ffi
+        sz = ffi.sizeof("struct C")
+        assert sz == ffi.sizeof("int *")