diff --git a/setup.py b/setup.py
index 9648d871..a63a2c66 100644
--- a/setup.py
+++ b/setup.py
@@ -6,6 +6,7 @@ import os
 import shutil
 import subprocess
 import sys
+import re
 
 from setuptools import Extension, setup
 from setuptools.command.install import install
@@ -64,6 +64,10 @@ def get_version():
     version = version.replace("tanglu", "+tanglu")
     version = version.split("build")[0]
 
+    # Trisquel-style suffix: "3.1.0trisquel12" -> "3.1.0+trisquel12" (PEP 440 local)
+    if "+" not in version:
+        version = re.sub(r"(?<=\d)([A-Za-z])", r"+\1", version, count=1)
+
     return version