diff --git a/Doc/library/zlib.rst b/Doc/library/zlib.rst
index 339acfd0e5786f..670a3cf2094744 100644
--- a/Doc/library/zlib.rst
+++ b/Doc/library/zlib.rst
@@ -47,6 +47,11 @@ The available exception and functions in this module are:
       platforms, use ``adler32(data) & 0xffffffff``.
 
 
+.. function:: adler32_combine(adler_1, adler_2, len_2)
+
+   Combines two Adler-32 checksums *adler_1* and *adler_2* into one. *len_2* is the length of the string used to generate *adler_2*.
+
+
 .. function:: compress(data, /, level=-1)
 
    Compresses the bytes in *data*, returning a bytes object containing compressed data.
diff --git a/Lib/test/test_zlib.py b/Lib/test/test_zlib.py
index f828b4c737a5fc..f25d7d0374d553 100644
--- a/Lib/test/test_zlib.py
+++ b/Lib/test/test_zlib.py
@@ -48,6 +48,9 @@ def test_adler32empty(self):
         self.assertEqual(zlib.adler32(b"", 1), 1)
         self.assertEqual(zlib.adler32(b"", 432), 432)
 
+    def test_adler32_combine(self):
+        self.assertEqual(zlib.adler32_combine(zlib.adler32(b"penguin"), zlib.adler32(b"banana"), len(b"banana")), 636028248)
+
     def test_penguins(self):
         self.assertEqual(zlib.crc32(b"penguin", 0), 0x0e5c1a120)
         self.assertEqual(zlib.crc32(b"penguin", 1), 0x43b6aa94)
diff --git a/Misc/ACKS b/Misc/ACKS
index 78beee5f34eec6..5ad249ccca8f11 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -1896,3 +1896,4 @@ Robert Leenders
 Tim Hopper
 Dan Lidral-Porter
 Ngalim Siregar
+Callum Attryde
diff --git a/Modules/clinic/zlibmodule.c.h b/Modules/clinic/zlibmodule.c.h
index 77ea04a353bf14..62fffd2d66fd39 100644
--- a/Modules/clinic/zlibmodule.c.h
+++ b/Modules/clinic/zlibmodule.c.h
@@ -704,6 +704,72 @@ zlib_adler32(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
     return return_value;
 }
 
+PyDoc_STRVAR(zlib_adler32_combine__doc__,
+"adler32_combine($module, adler_1, adler_2, len_2, /)\n"
+"--\n"
+"\n"
+"Combine two Adler-32 Checksums into one.\n"
+"\n"
+"  adler_1\n"
+"    First checksum.\n"
+"  adler_2\n"
+"    Second checksum.\n"
+"  len_2\n"
+"    Length of the buffer used to generate the second checksum.\n"
+"\n"
+"The returned checksum is an integer.");
+
+#define ZLIB_ADLER32_COMBINE_METHODDEF    \
+    {"adler32_combine", (PyCFunction)(void(*)(void))zlib_adler32_combine, METH_FASTCALL, zlib_adler32_combine__doc__},
+
+static PyObject *
+zlib_adler32_combine_impl(PyObject *module, unsigned int adler_1,
+                          unsigned int adler_2, unsigned int len_2);
+
+static PyObject *
+zlib_adler32_combine(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
+{
+    PyObject *return_value = NULL;
+    unsigned int adler_1;
+    unsigned int adler_2;
+    unsigned int len_2;
+
+    if (!_PyArg_CheckPositional("adler32_combine", nargs, 3, 3)) {
+        goto exit;
+    }
+    if (PyFloat_Check(args[0])) {
+        PyErr_SetString(PyExc_TypeError,
+                        "integer argument expected, got float" );
+        goto exit;
+    }
+    adler_1 = (unsigned int)PyLong_AsUnsignedLongMask(args[0]);
+    if (adler_1 == (unsigned int)-1 && PyErr_Occurred()) {
+        goto exit;
+    }
+    if (PyFloat_Check(args[1])) {
+        PyErr_SetString(PyExc_TypeError,
+                        "integer argument expected, got float" );
+        goto exit;
+    }
+    adler_2 = (unsigned int)PyLong_AsUnsignedLongMask(args[1]);
+    if (adler_2 == (unsigned int)-1 && PyErr_Occurred()) {
+        goto exit;
+    }
+    if (PyFloat_Check(args[2])) {
+        PyErr_SetString(PyExc_TypeError,
+                        "integer argument expected, got float" );
+        goto exit;
+    }
+    len_2 = (unsigned int)PyLong_AsUnsignedLongMask(args[2]);
+    if (len_2 == (unsigned int)-1 && PyErr_Occurred()) {
+        goto exit;
+    }
+    return_value = zlib_adler32_combine_impl(module, adler_1, adler_2, len_2);
+
+exit:
+    return return_value;
+}
+
 PyDoc_STRVAR(zlib_crc32__doc__,
 "crc32($module, data, value=0, /)\n"
 "--\n"
@@ -785,4 +851,4 @@ zlib_crc32(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
 #ifndef ZLIB_DECOMPRESS___DEEPCOPY___METHODDEF
     #define ZLIB_DECOMPRESS___DEEPCOPY___METHODDEF
 #endif /* !defined(ZLIB_DECOMPRESS___DEEPCOPY___METHODDEF) */
-/*[clinic end generated code: output=faae38ef96b88b16 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=0922ad853778187c input=a9049054013a1b77]*/
diff --git a/Modules/zlibmodule.c b/Modules/zlibmodule.c
index 3e77080a31cb57..b646663347f3fa 100644
--- a/Modules/zlibmodule.c
+++ b/Modules/zlibmodule.c
@@ -1264,6 +1264,31 @@ zlib_adler32_impl(PyObject *module, Py_buffer *data, unsigned int value)
     return PyLong_FromUnsignedLong(value & 0xffffffffU);
 }
 
+/*[clinic input]
+zlib.adler32_combine
+
+    adler_1: unsigned_int(bitwise=True)
+        First checksum.
+    adler_2: unsigned_int(bitwise=True)
+        Second checksum.
+    len_2: unsigned_int(bitwise=True)
+        Length of the buffer used to generate the second checksum.
+    /
+
+Combine two Adler-32 Checksums into one.
+
+The returned checksum is an integer.
+[clinic start generated code]*/
+
+static PyObject *
+zlib_adler32_combine_impl(PyObject *module, unsigned int adler_1,
+                          unsigned int adler_2, unsigned int len_2)
+/*[clinic end generated code: output=af156f2b847877ae input=c436395ab679bbc2]*/
+{
+	unsigned long value = adler32_combine64(adler_1, adler_2, len_2);
+	return PyLong_FromUnsignedLong(value & 0xffffffffU);
+}
+
 /*[clinic input]
 zlib.crc32
 
@@ -1309,6 +1334,7 @@ zlib_crc32_impl(PyObject *module, Py_buffer *data, unsigned int value)
 static PyMethodDef zlib_methods[] =
 {
     ZLIB_ADLER32_METHODDEF
+    ZLIB_ADLER32_COMBINE_METHODDEF
     ZLIB_COMPRESS_METHODDEF
     ZLIB_COMPRESSOBJ_METHODDEF
     ZLIB_CRC32_METHODDEF
@@ -1351,6 +1377,7 @@ PyDoc_STRVAR(zlib_module_documentation,
 "zlib library, which is based on GNU zip.\n"
 "\n"
 "adler32(string[, start]) -- Compute an Adler-32 checksum.\n"
+"adler32_combine(adler1, adler2, len2) -- Combine two Adler-32 checksums.\n"
 "compress(data[, level]) -- Compress data, with compression level 0-9 or -1.\n"
 "compressobj([level[, ...]]) -- Return a compressor object.\n"
 "crc32(string[, start]) -- Compute a CRC-32 checksum.\n"