diff --git a/pyteomics/mgf.py b/pyteomics/mgf.py
index 8746e7dd..811e43eb 100644
--- a/pyteomics/mgf.py
+++ b/pyteomics/mgf.py
@@ -609,7 +609,11 @@ def _pepmass_repr(k, pepmass):
 
 
 def _charge_repr(k, charge):
-    return '{}={}'.format(k.upper(), aux.Charge(charge) if isinstance(charge, int) else aux.ChargeList(charge))
+    try:
+        val = aux.Charge(charge)
+    except (TypeError, aux.PyteomicsError):
+        val = aux.ChargeList(charge)
+    return '{}={}'.format(k.upper(), val)
 
 
 def _default_repr(key, val):
diff --git a/pyteomics/version.py b/pyteomics/version.py
index a3a43e45..2b310b6c 100644
--- a/pyteomics/version.py
+++ b/pyteomics/version.py
@@ -19,7 +19,7 @@
 
 """
 
-__version__ = '4.6.2'
+__version__ = '4.6.3a1'
 
 from collections import namedtuple
 import re
diff --git a/tests/test_mgf.py b/tests/test_mgf.py
index 7f4dd397..5d690fca 100644
--- a/tests/test_mgf.py
+++ b/tests/test_mgf.py
@@ -252,11 +252,13 @@ def test_charge_repr_single(self):
         self.assertEqual(mgf._charge_repr('charge', [2]), 'CHARGE=2+')
         self.assertEqual(mgf._charge_repr('charge', aux.Charge(2)), 'CHARGE=2+')
         self.assertEqual(mgf._charge_repr('charge', aux.ChargeList([2])), 'CHARGE=2+')
+        self.assertEqual(mgf._charge_repr('charge', np.int64(2)), 'CHARGE=2+')
 
     def test_charge_repr_multiple(self):
         self.assertEqual(mgf._charge_repr('charge', [2, 3]), 'CHARGE=2+ and 3+')
         self.assertEqual(mgf._charge_repr('charge', aux.ChargeList([2, 3])), 'CHARGE=2+ and 3+')
         self.assertEqual(mgf._charge_repr('charge', '2+, 3+'), 'CHARGE=2+ and 3+')
+        self.assertEqual(mgf._charge_repr('charge', np.array([2, 3])), 'CHARGE=2+ and 3+')
 
 
 if __name__ == "__main__":