diff --git a/doc/builders/fetchers.chapter.md b/doc/builders/fetchers.chapter.md
index 4d4f3f427cd4..ba105764904c 100644
--- a/doc/builders/fetchers.chapter.md
+++ b/doc/builders/fetchers.chapter.md
@@ -82,6 +82,53 @@ Note that because the checksum is computed after applying these effects, using o
 
 Most other fetchers return a directory rather than a single file.
 
+
+## `fetchDebianPatch` {#fetchdebianpatch}
+
+A wrapper around `fetchpatch`, which takes:
+- `patch` and `hash`: the patch's filename without the `.patch` suffix,
+  and its hash after normalization by `fetchpatch` ;
+- `pname`: the Debian source package's name ;
+- `version`: the upstream version number ;
+- `debianRevision`: the [Debian revision number] if applicable ;
+- the `area` of the Debian archive: `main` (default), `contrib`, or `non-free`.
+
+Here is an example of `fetchDebianPatch` in action:
+
+```nix
+{ lib
+, fetchDebianPatch
+, buildPythonPackage
+}:
+
+buildPythonPackage rec {
+  pname = "pysimplesoap";
+  version = "1.16.2";
+  src = ...;
+
+  patches = [
+    (fetchDebianPatch {
+      inherit pname version;
+      debianRevision = "5";
+      name = "Add-quotes-to-SOAPAction-header-in-SoapClient";
+      hash = "sha256-xA8Wnrpr31H8wy3zHSNfezFNjUJt1HbSXn3qUMzeKc0=";
+    })
+  ];
+
+  ...
+}
+```
+
+Patches are fetched from `sources.debian.org`, and so must come from a
+package version that was uploaded to the Debian archive.  Packages may
+be removed from there once that specific version isn't in any suite
+anymore (stable, testing, unstable, etc.), so maintainers should use
+`copy-tarballs.pl` to archive the patch if it needs to be available
+longer-term.
+
+[Debian revision number]: https://www.debian.org/doc/debian-policy/ch-controlfields.html#version
+
+
 ## `fetchsvn` {#fetchsvn}
 
 Used with Subversion. Expects `url` to a Subversion directory, `rev`, and `hash`.
diff --git a/pkgs/build-support/fetchdebianpatch/default.nix b/pkgs/build-support/fetchdebianpatch/default.nix
new file mode 100644
index 000000000000..c058b416d381
--- /dev/null
+++ b/pkgs/build-support/fetchdebianpatch/default.nix
@@ -0,0 +1,19 @@
+{ lib, fetchpatch }:
+
+lib.makeOverridable (
+  { pname, version, debianRevision ? null, patch, hash,
+    area ? "main", name ? "${patch}.patch" }:
+  let
+    inherit (lib.strings) hasPrefix substring;
+    prefix =
+      substring 0 (if hasPrefix "lib" pname then 4 else 1) pname;
+    versionString =
+      if debianRevision == null then version
+      else "${version}-${debianRevision}";
+  in fetchpatch {
+    inherit name hash;
+    url =
+      "https://sources.debian.org/data/${area}/${prefix}/"
+      + "${pname}/${versionString}/debian/patches/${patch}.patch";
+  }
+)
diff --git a/pkgs/build-support/fetchdebianpatch/tests.nix b/pkgs/build-support/fetchdebianpatch/tests.nix
new file mode 100644
index 000000000000..58f3b395d1fc
--- /dev/null
+++ b/pkgs/build-support/fetchdebianpatch/tests.nix
@@ -0,0 +1,19 @@
+{ testers, fetchDebianPatch, ... }:
+
+{
+  simple = testers.invalidateFetcherByDrvHash fetchDebianPatch {
+    pname = "pysimplesoap";
+    version = "1.16.2";
+    debianRevision = "5";
+    patch = "Add-quotes-to-SOAPAction-header-in-SoapClient";
+    hash = "sha256-xA8Wnrpr31H8wy3zHSNfezFNjUJt1HbSXn3qUMzeKc0=";
+  };
+
+  libPackage = testers.invalidateFetcherByDrvHash fetchDebianPatch {
+    pname = "libfile-pid-perl";
+    version = "1.01";
+    debianRevision = "2";
+    patch = "missing-pidfile";
+    hash = "sha256-VBsIYyCnjcZLYQ2Uq2MKPK3kF2wiMKvnq0m727DoavM=";
+  };
+}
diff --git a/pkgs/development/python-modules/pysimplesoap/default.nix b/pkgs/development/python-modules/pysimplesoap/default.nix
index 11ffdaa7aa58..eecf54425380 100644
--- a/pkgs/development/python-modules/pysimplesoap/default.nix
+++ b/pkgs/development/python-modules/pysimplesoap/default.nix
@@ -1,5 +1,5 @@
 { lib
-, fetchpatch
+, fetchDebianPatch
 , fetchPypi
 , buildPythonPackage
 , m2crypto
@@ -20,28 +20,24 @@ buildPythonPackage rec {
     m2crypto
   ];
 
-  patches =
-    let
-      debianRevision = "5";  # The Debian package revision we get patches from
-      fetchDebianPatch = { name, hash }: fetchpatch {
-        url = "https://salsa.debian.org/python-team/packages/pysimplesoap/-/raw/debian/${version}-${debianRevision}/debian/patches/${name}.patch";
-        inherit hash;
-      };
-    in map fetchDebianPatch [
-      # Merged upstream: f5f96210e1483f81cb5c582a6619e3ec4b473027
-      { name = "Add-quotes-to-SOAPAction-header-in-SoapClient";
-        hash = "sha256-xA8Wnrpr31H8wy3zHSNfezFNjUJt1HbSXn3qUMzeKc0="; }
-      # Merged upstream: ad03a21cafab982eed321553c4bfcda1755182eb
-      { name = "fix-httplib2-version-check";
-        hash = "sha256-zUeF3v0N/eMyRVRH3tQLfuUfMKOD/B/aqEwFh/7HxH4="; }
-      { name = "reorder-type-check-to-avoid-a-TypeError";
-        hash = "sha256-2p5Cqvh0SPfJ8B38wb/xq7jWGYgpI9pavA6qkMUb6hA="; }
-      # Merged upstream: 033e5899e131a2c1bdf7db5852f816f42aac9227
-      { name = "Support-integer-values-in-maxOccurs-attribute";
-        hash = "sha256-IZ0DP7io+ihcnB5547cR53FAdnpRLR6z4J5KsNrkfaI="; }
-      { name = "PR204";
-        hash = "sha256-JlxeTnKDFxvEMFBthZsaYRbNOoBvLJhBnXCRoiL/nVw="; }
-    ] ++ [ ./stringIO.patch ];
+  patches = map (args: fetchDebianPatch ({
+    inherit pname version;
+    debianRevision = "5";
+  } // args)) [
+    # Merged upstream: f5f96210e1483f81cb5c582a6619e3ec4b473027
+    { patch = "Add-quotes-to-SOAPAction-header-in-SoapClient";
+      hash = "sha256-xA8Wnrpr31H8wy3zHSNfezFNjUJt1HbSXn3qUMzeKc0="; }
+    # Merged upstream: ad03a21cafab982eed321553c4bfcda1755182eb
+    { patch = "fix-httplib2-version-check";
+      hash = "sha256-zUeF3v0N/eMyRVRH3tQLfuUfMKOD/B/aqEwFh/7HxH4="; }
+    { patch = "reorder-type-check-to-avoid-a-TypeError";
+      hash = "sha256-2p5Cqvh0SPfJ8B38wb/xq7jWGYgpI9pavA6qkMUb6hA="; }
+    # Merged upstream: 033e5899e131a2c1bdf7db5852f816f42aac9227
+    { patch = "Support-integer-values-in-maxOccurs-attribute";
+      hash = "sha256-IZ0DP7io+ihcnB5547cR53FAdnpRLR6z4J5KsNrkfaI="; }
+    { patch = "PR204";
+      hash = "sha256-JlxeTnKDFxvEMFBthZsaYRbNOoBvLJhBnXCRoiL/nVw="; }
+  ] ++ [ ./stringIO.patch ];
 
   meta = with lib; {
     description = "Python simple and lightweight SOAP Library";
diff --git a/pkgs/test/default.nix b/pkgs/test/default.nix
index b9d75c790da6..d6fd75359fc4 100644
--- a/pkgs/test/default.nix
+++ b/pkgs/test/default.nix
@@ -35,6 +35,7 @@ with pkgs;
   fetchurl = callPackages ../build-support/fetchurl/tests.nix { };
   fetchpatch = callPackages ../build-support/fetchpatch/tests.nix { };
   fetchpatch2 = callPackages ../build-support/fetchpatch/tests.nix { fetchpatch = fetchpatch2; };
+  fetchDebianPatch = callPackages ../build-support/fetchdebianpatch/tests.nix { };
   fetchzip = callPackages ../build-support/fetchzip/tests.nix { };
   fetchgit = callPackages ../build-support/fetchgit/tests.nix { };
   fetchFirefoxAddon = callPackages ../build-support/fetchfirefoxaddon/tests.nix { };
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index cdf7e922f51f..d173e7ebdd88 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -1175,6 +1175,11 @@ with pkgs;
       tests = pkgs.tests.fetchzip;
     };
 
+  fetchDebianPatch = callPackage ../build-support/fetchdebianpatch { }
+    // {
+      tests = pkgs.tests.fetchDebianPatch;
+    };
+
   fetchCrate = callPackage ../build-support/rust/fetchcrate.nix { };
 
   fetchFromGitea = callPackage ../build-support/fetchgitea { };