diff -Nru dput-1.1.3ubuntu2/debian/changelog dput-1.1.3ubuntu2.1/debian/changelog
--- dput-1.1.3ubuntu2/debian/changelog	2023-02-16 22:38:56.000000000 +0100
+++ dput-1.1.3ubuntu2.1/debian/changelog	2023-07-01 01:49:41.000000000 +0200
@@ -1,3 +1,9 @@
+dput (1.1.3ubuntu2.1) lunar; urgency=medium
+
+  * Make PEP 440 version conversion more robust for SRUs (LP: #1991606)
+
+ -- Benjamin Drung <bdrung@ubuntu.com>  Sat, 01 Jul 2023 01:49:41 +0200
+
 dput (1.1.3ubuntu2) lunar; urgency=medium
 
   * Make versions with Ubuntu suffixes compliant with PEP 440.
diff -Nru dput-1.1.3ubuntu2/setup.py dput-1.1.3ubuntu2.1/setup.py
--- dput-1.1.3ubuntu2/setup.py	2023-02-16 22:33:45.000000000 +0100
+++ dput-1.1.3ubuntu2.1/setup.py	2023-07-01 01:49:35.000000000 +0200
@@ -22,6 +22,22 @@
         setup,
         )
 
+
+def make_pep440_compliant(version: str) -> str:
+    """Convert the version into a PEP440 compliant version."""
+    public_version_re = re.compile(
+        r"^([0-9][0-9.]*(?:(?:a|b|rc|.post|.dev)[0-9]+)*)\+?"
+    )
+    _, public, local = public_version_re.split(version, maxsplit=1)
+    if not local:
+        return version
+    sanitized_local = re.sub("[+~]+", ".", local).strip(".")
+    pep440_version = f"{public}+{sanitized_local}"
+    assert re.match(
+        "^[a-zA-Z0-9.]+$", sanitized_local
+    ), f"'{pep440_version}' not PEP440 compliant"
+    return pep440_version
+
 
 setup_dir = os.path.dirname(__file__)
 
@@ -40,11 +56,6 @@
 (maintainer_name, maintainer_email) = email.utils.parseaddr(
         control_structure['maintainer'])
 
-# According to PEP 440, an ubuntuX suffix is considered an invalid version
-# Make the version compliant (e.g. 1.1.3ubuntu2 -> 1.1.3.post2)
-if bool(re.match(r"([0-9]+(\.[0-9]+)+)ubuntu[0-9]+", str(changelog.version))):
-    changelog.version = str(changelog.version).replace("ubuntu", ".post")
-
 copyright_file_path = os.path.join(setup_dir, "debian", "copyright")
 with open(copyright_file_path) as copyright_file:
     copyright_structure = debian.copyright.Copyright(copyright_file)
@@ -61,7 +72,7 @@
 
 setup_kwargs = dict(
         name=changelog.package,
-        version=str(changelog.version),
+        version=make_pep440_compliant(str(changelog.version)),
         packages=find_packages(exclude=["test"]),
 
         # Setuptools metadata.