diff --git a/pkgs/os-specific/linux/kernel/update-mainline.py b/pkgs/os-specific/linux/kernel/update-mainline.py
index 79ac283faab6..320d5065fefa 100755
--- a/pkgs/os-specific/linux/kernel/update-mainline.py
+++ b/pkgs/os-specific/linux/kernel/update-mainline.py
@@ -1,5 +1,6 @@
 #!/usr/bin/env nix-shell
 #!nix-shell -i python3 -p "python3.withPackages (ps: [ ps.beautifulsoup4 ps.lxml ps.packaging ])"
+from functools import cached_property
 from itertools import groupby
 import json
 import os
@@ -29,20 +30,33 @@ class KernelNature(Enum):
 class KernelRelease:
     nature: KernelNature
     version: str
-    branch: str
     date: str
     link: str
     eol: bool = False
 
+    @cached_property
+    def parsed_version(self) -> Version:
+        return parse_version(self.version)
+
+    @cached_property
+    def branch(self) -> str:
+        version = self.parsed_version
+        # This is a testing kernel.
+        if version.is_prerelease:
+            return "testing"
+        else:
+            return f"{version.major}.{version.minor}"
+
 
 def parse_release(release: Tag) -> KernelRelease | None:
     columns: list[Tag] = list(release.find_all("td"))
     try:
         nature = KernelNature[columns[0].get_text().rstrip(":").upper()]
     except KeyError:
+        # skip linux-next
         return None
 
-    version = parse_version(columns[1].get_text().rstrip(" [EOL]"))
+    version = columns[1].get_text().rstrip(" [EOL]")
     date = columns[2].get_text()
     link = columns[3].find("a")
     if link is not None and isinstance(link, Tag):
@@ -52,7 +66,6 @@ def parse_release(release: Tag) -> KernelRelease | None:
 
     return KernelRelease(
         nature=nature,
-        branch=get_branch(version),
         version=version,
         date=date,
         link=link,
@@ -60,14 +73,6 @@ def parse_release(release: Tag) -> KernelRelease | None:
     )
 
 
-def get_branch(version: Version):
-    # This is a testing kernel.
-    if version.is_prerelease:
-        return "testing"
-    else:
-        return f"{version.major}.{version.minor}"
-
-
 def get_hash(kernel: KernelRelease):
     if kernel.branch == "testing":
         args = ["--unpack"]
@@ -108,16 +113,19 @@ def main():
         sys.exit(1)
 
     releases = release_table.find_all("tr")
-    parsed_releases = filter(None, [parse_release(release) for release in releases])
+    parsed_releases = [
+        parsed for release in releases
+        if (parsed := parse_release(release)) is not None
+    ]
     all_kernels = json.load(VERSIONS_FILE.open())
 
     oldest_branch = get_oldest_branch()
 
-    for (branch, kernels) in groupby(parsed_releases, lambda kernel: get_branch(kernel.version)):
-        kernel = max(kernels, key=lambda kernel: kernel.version)
+    for (branch, kernels) in groupby(parsed_releases, lambda kernel: kernel.branch):
+        kernel = max(kernels, key=lambda kernel: kernel.parsed_version)
         nixpkgs_branch = branch.replace(".", "_")
 
-        old_version = parse_version(all_kernels.get(branch, {}).get("version"))
+        old_version = all_kernels.get(branch, {}).get("version")
         if old_version == kernel.version:
             print(f"linux_{nixpkgs_branch}: {kernel.version} is latest, skipping...")
             continue
@@ -144,7 +152,7 @@ def main():
         print(message, file=sys.stderr)
 
         all_kernels[branch] = {
-            "version": str(kernel.version),
+            "version": kernel.version,
             "hash": get_hash(kernel),
         }