diff -up lib/core/src/perl/RefHash.xxs.orig lib/core/src/perl/RefHash.xxs
--- a/lib/core/src/perl/RefHash.xxs	2022-06-06 10:35:17.689807548 +0200
+++ b/lib/core/src/perl/RefHash.xxs	2022-06-06 10:37:12.935663947 +0200
@@ -71,7 +71,11 @@ SV* tmp_keysv::set(SV* keysv)
    Copy(obj.keyp, HEK_KEY(hekp), sizeof(SV*), char);
    HEK_LEN(hekp) = sizeof(SV*);
    HEK_HASH(hekp) = U32(obj.keyl >> 4);          // hash value
+#if PerlVersion < 5360
    HEK_FLAGS(hekp) = HVhek_UNSHARED;
+#else
+   HEK_FLAGS(hekp) = HVhek_NOTSHARED;
+#endif
    sv.sv_any = &xpv;
    sv.sv_refcnt = 1;
    sv.sv_flags = SVt_PVIV | SVf_IVisUV | SVf_POK | SVp_POK | PmFlagsForHashKey;