diff --git a/graalpython/com.oracle.graal.python.test/src/tests/test_struct.py b/graalpython/com.oracle.graal.python.test/src/tests/test_struct.py
index 4fde738440..b0a9b26cb9 100644
--- a/graalpython/com.oracle.graal.python.test/src/tests/test_struct.py
+++ b/graalpython/com.oracle.graal.python.test/src/tests/test_struct.py
@@ -1,4 +1,4 @@
-# Copyright (c) 2020, 2024, Oracle and/or its affiliates. All rights reserved.
+# Copyright (c) 2020, 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
@@ -187,6 +187,14 @@ def test_pack_large_long():
         assert struct.unpack(fmt, b'\xff' * size) == (maxval,)
 
 
+def test_pack_void_ptr_unsigned_range():
+    size = struct.calcsize('P')
+    maxval = (1 << (size * 8)) - 1
+    assert struct.pack('P', maxval) == b'\xff' * size
+    assert struct.unpack('P', struct.pack('P', -1)) == (maxval,)
+    assert_raises(struct.error, struct.pack, 'P', maxval + 1)
+
+
 def test_pack_into():
     test_string = b'Reykjavik rocks, eow!'
     writable_buf = bytearray(b' '*100)
diff --git a/graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/struct/StructNodes.java b/graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/struct/StructNodes.java
index 1bc0414aeb..a0cf2d8d1c 100644
--- a/graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/struct/StructNodes.java
+++ b/graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/struct/StructNodes.java
@@ -1,4 +1,4 @@
-/* Copyright (c) 2020, 2025, Oracle and/or its affiliates.
+/* Copyright (c) 2020, 2026, Oracle and/or its affiliates.
  * Copyright (C) 1996-2020 Python Software Foundation
  *
  * Licensed under the PYTHON SOFTWARE FOUNDATION LICENSE VERSION 2
@@ -115,8 +115,9 @@ static long get(VirtualFrame frame, Object value, boolean unsigned,
     // ------------------------------------------------------------------------------------------------------------
     @ImportStatic({PGuards.class})
     public abstract static class StructBaseNode extends PNodeWithContext {
-        public static final BigInteger UBYTE_MASK = BigInteger.valueOf(0xff);
-        public static final BigInteger ULONG_MASK = BigInteger.ONE.shiftLeft(Long.SIZE).subtract(BigInteger.ONE);
+        private static final BigInteger ULONG_MASK = BigInteger.ONE.shiftLeft(Long.SIZE).subtract(BigInteger.ONE);
+        protected static final BigInteger PTR_SIGNED_MIN = BigInteger.valueOf(Long.MIN_VALUE);
+        protected static final BigInteger PTR_UNSIGNED_MAX = ULONG_MASK;
 
         public static int getNumBytesLimit() {
             return NUM_BYTES_LIMIT;
@@ -202,6 +203,18 @@ public static BigInteger getAsUnsignedBigInt(long value) {
             return BigInteger.valueOf(value).and(ULONG_MASK);
         }
 
+        @TruffleBoundary
+        public static long checkVoidPtr(Node raisingNode, BigInteger value) {
+            if (value.signum() < 0) {
+                if (value.compareTo(PTR_SIGNED_MIN) < 0) {
+                    throw PRaiseNode.raiseStatic(raisingNode, StructError, ARG_O_O_RANGE);
+                }
+            } else if (value.compareTo(PTR_UNSIGNED_MAX) > 0) {
+                throw PRaiseNode.raiseStatic(raisingNode, StructError, ARG_O_O_RANGE);
+            }
+            return value.longValue();
+        }
+
         public static long handleSign(FormatCode code, long num) {
             // handle the sign extension (2's complement)
             long value = num;
@@ -369,8 +382,14 @@ static void packObjectCached(VirtualFrame frame, FormatCode formatCode, FormatAl
                 }
                 packFloat(formatCode, formatAlignment, asDoubleNode.execute(frame, inliningTarget, value), buffer, offset, inliningTarget, numericSupport, raiseNode);
             } else if (isFmtVoidPtr(formatCode)) {
-                getLongNode.execute(frame, value, formatCode.isUnsigned());
-                packLong(formatCode, formatAlignment, getLongNode.execute(frame, value, formatCode.isUnsigned()), buffer, offset, inliningTarget, numericSupport, profileSigned, raiseNode);
+                BigInteger num;
+                try {
+                    num = toJavaBigIntegerNode.execute(inliningTarget, value);
+                } catch (PException pe) {
+                    pe.expect(inliningTarget, PythonBuiltinClassType.TypeError, errorProfile);
+                    throw raiseNode.raise(inliningTarget, StructError, ARG_NOT_T, "an integer");
+                }
+                numericSupport.putLong(buffer, offset, checkVoidPtr(inliningTarget, num), formatCode.numBytes());
             } else if (isFmtBoolean(formatCode)) {
                 packBoolean(formatCode, formatAlignment, isTrueNode.execute(frame, value), buffer, offset);
             } else if (isFmtBytes(formatCode)) {