diff -ur meliae-0.5.1/meliae/_scanner_core.c meliae-0.5.1-patched/meliae/_scanner_core.c
--- meliae-0.5.1/meliae/_scanner_core.c	2020-02-05 15:29:03.000000000 +0300
+++ meliae-0.5.1-patched/meliae/_scanner_core.c	2020-05-17 01:10:38.856660322 +0300
@@ -595,6 +595,7 @@
     int retval;
     int do_traverse;
     const char *name;
+    int overflow;
 
     if (info->nodump != NULL && 
         info->nodump != Py_None
@@ -676,7 +677,7 @@
         _write_to_ref_info(info, ", \"value\": %ld", PyInt_AS_LONG(c_obj));
 #endif
     } else if (PyLong_CheckExact(c_obj)) {
-        _write_to_ref_info(info, ", \"value\": %ld", PyLong_AsLong(c_obj));
+        _write_to_ref_info(info, ", \"value\": %lld", PyLong_AsLongLongAndOverflow(c_obj, &overflow));
     } else if (PyTuple_Check(c_obj)) {
         _write_to_ref_info(info, ", \"len\": " SSIZET_FMT, PyTuple_GET_SIZE(c_obj));
     } else if (PyList_Check(c_obj)) {