diff --git a/graalpython/com.oracle.graal.python.test/src/tests/test_operator.py b/graalpython/com.oracle.graal.python.test/src/tests/test_operator.py
index ed526c81d7..138f2cebc3 100644
--- a/graalpython/com.oracle.graal.python.test/src/tests/test_operator.py
+++ b/graalpython/com.oracle.graal.python.test/src/tests/test_operator.py
@@ -67,3 +67,25 @@ def test_getitem(self):
         self.assertRaises(TypeError, operator.getitem)
         self.assertRaises(TypeError, operator.getitem, a, None)
         self.assertEqual(operator.getitem(a, 2), 2)
+
+    def test_setitem_delitem_convert_index_before_type_error(self):
+        class RaisingIndex:
+            def __index__(self):
+                raise ZeroDivisionError
+
+        class Plain:
+            pass
+
+        self.assertRaises(ZeroDivisionError, operator.setitem, (), RaisingIndex(), 0)
+        self.assertRaises(ZeroDivisionError, operator.setitem, frozenset(), RaisingIndex(), 0)
+        self.assertRaises(ZeroDivisionError, operator.setitem, Plain(), RaisingIndex(), 0)
+        self.assertRaises(IndexError, operator.setitem, '', 2**100, 0)
+        self.assertRaises(ZeroDivisionError, operator.delitem, '', RaisingIndex())
+        self.assertRaises(ZeroDivisionError, operator.delitem, Plain(), RaisingIndex())
+        self.assertRaises(IndexError, operator.delitem, (), 2**100)
+        self.assertRaises(TypeError, operator.setitem, (), 2**40, 0)
+        self.assertRaises(TypeError, operator.delitem, '', 2**40)
+        self.assertRaises(TypeError, operator.setitem, (), 0, 0)
+        self.assertRaises(TypeError, operator.delitem, (), 'a')
+        self.assertRaises(TypeError, operator.setitem, 1, RaisingIndex(), 0)
+        self.assertRaises(TypeError, operator.delitem, list[int], RaisingIndex())
diff --git a/graalpython/com.oracle.graal.python/src/com/oracle/graal/python/lib/PyObjectDelItem.java b/graalpython/com.oracle.graal.python/src/com/oracle/graal/python/lib/PyObjectDelItem.java
index 14e3d3cc33..2055eb00a8 100644
--- a/graalpython/com.oracle.graal.python/src/com/oracle/graal/python/lib/PyObjectDelItem.java
+++ b/graalpython/com.oracle.graal.python/src/com/oracle/graal/python/lib/PyObjectDelItem.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021, 2025, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2021, 2026, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * The Universal Permissive License (UPL), Version 1.0
@@ -40,9 +40,11 @@
  */
 package com.oracle.graal.python.lib;
 
+import static com.oracle.graal.python.builtins.PythonBuiltinClassType.IndexError;
 import static com.oracle.graal.python.builtins.PythonBuiltinClassType.TypeError;
 
 import com.oracle.graal.python.builtins.objects.PNone;
+import com.oracle.graal.python.builtins.objects.ints.PInt;
 import com.oracle.graal.python.builtins.objects.list.ListBuiltins;
 import com.oracle.graal.python.builtins.objects.list.PList;
 import com.oracle.graal.python.builtins.objects.type.TpSlots;
@@ -124,6 +126,17 @@ static void doSequence(VirtualFrame frame, Node inliningTarget, Object object, T
             callSqItem.execute(frame, inliningTarget, slots.sq_ass_item(), object, index, PNone.NO_VALUE);
         }
 
+        @Specialization(guards = {"slots.mp_ass_subscript() == null", "slots.sq_ass_item() == null", "slots.has_as_sequence()"})
+        @InliningCutoff
+        static void doSequenceNoAssItem(VirtualFrame frame, Node inliningTarget, Object object, @SuppressWarnings("unused") TpSlots slots, Object key,
+                        @Cached PyIndexCheckNode indexCheckNode,
+                        @Cached PyNumberIndexNode indexNode) {
+            if (indexCheckNode.execute(inliningTarget, key) && indexNode.execute(frame, inliningTarget, key) instanceof PInt pint && pint.bitLength() >= Long.SIZE) {
+                throw PRaiseNode.raiseStatic(inliningTarget, IndexError, ErrorMessages.CANNOT_FIT_P_INTO_INDEXSIZED_INT, key);
+            }
+            throw PRaiseNode.raiseStatic(inliningTarget, TypeError, ErrorMessages.OBJ_DOES_NOT_SUPPORT_ITEM_DELETION, object);
+        }
+
         @Fallback
         @InliningCutoff
         static void error(Object object, @SuppressWarnings("unused") TpSlots slots, @SuppressWarnings("unused") Object key,
diff --git a/graalpython/com.oracle.graal.python/src/com/oracle/graal/python/lib/PyObjectSetItem.java b/graalpython/com.oracle.graal.python/src/com/oracle/graal/python/lib/PyObjectSetItem.java
index 1ee239c79b..671e864b95 100644
--- a/graalpython/com.oracle.graal.python/src/com/oracle/graal/python/lib/PyObjectSetItem.java
+++ b/graalpython/com.oracle.graal.python/src/com/oracle/graal/python/lib/PyObjectSetItem.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021, 2025, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2021, 2026, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * The Universal Permissive License (UPL), Version 1.0
@@ -40,8 +40,10 @@
  */
 package com.oracle.graal.python.lib;
 
+import static com.oracle.graal.python.builtins.PythonBuiltinClassType.IndexError;
 import static com.oracle.graal.python.builtins.PythonBuiltinClassType.TypeError;
 
+import com.oracle.graal.python.builtins.objects.ints.PInt;
 import com.oracle.graal.python.builtins.objects.list.ListBuiltins;
 import com.oracle.graal.python.builtins.objects.list.PList;
 import com.oracle.graal.python.builtins.objects.type.TpSlots;
@@ -131,6 +133,17 @@ static void doSequence(VirtualFrame frame, Node inliningTarget, Object object, T
             callSqItem.execute(frame, inliningTarget, slots.sq_ass_item(), object, index, value);
         }
 
+        @Specialization(guards = {"slots.mp_ass_subscript() == null", "slots.sq_ass_item() == null", "slots.has_as_sequence()"})
+        @InliningCutoff
+        static void doSequenceNoAssItem(VirtualFrame frame, Node inliningTarget, Object object, @SuppressWarnings("unused") TpSlots slots, Object key, @SuppressWarnings("unused") Object value,
+                        @Cached PyIndexCheckNode indexCheckNode,
+                        @Cached PyNumberIndexNode indexNode) {
+            if (indexCheckNode.execute(inliningTarget, key) && indexNode.execute(frame, inliningTarget, key) instanceof PInt pint && pint.bitLength() >= Long.SIZE) {
+                throw PRaiseNode.raiseStatic(inliningTarget, IndexError, ErrorMessages.CANNOT_FIT_P_INTO_INDEXSIZED_INT, key);
+            }
+            throw PRaiseNode.raiseStatic(inliningTarget, TypeError, ErrorMessages.OBJ_DOES_NOT_SUPPORT_ITEM_ASSIGMENT, object);
+        }
+
         @Fallback
         @InliningCutoff
         static void error(Object object, @SuppressWarnings("unused") TpSlots slots, @SuppressWarnings("unused") Object key, @SuppressWarnings("unused") Object value,