diff --git a/lzomodule.c b/lzomodule.c
index ae5fa19..62d2cf8 100644
--- a/lzomodule.c
+++ b/lzomodule.c
@@ -29,7 +29,9 @@
  */
 
 
-#define MODULE_VERSION  "1.16"
+#ifndef MODULE_VERSION
+#  define MODULE_VERSION  "unknown"
+#endif
 
 #define PY_SSIZE_T_CLEAN
 
diff --git a/setup.py b/setup.py
index c1b1595..3b9aa4b 100644
--- a/setup.py
+++ b/setup.py
@@ -4,6 +4,7 @@
 from __future__ import print_function
 
 import os
+import re
 import shutil
 import subprocess
 import sys
@@ -12,6 +13,18 @@
 from setuptools import Command, Extension, setup
 
 
+def _get_version():
+    with open("pyproject.toml", "r") as f:
+        for line in f:
+            m = re.match(r'^version\s*=\s*"([^"]+)"', line)
+            if m:
+                return m.group(1)
+    return "unknown"
+
+
+_package_version = _get_version()
+
+
 class TestCommand(Command):
     user_options = []
 
@@ -72,6 +85,7 @@ def has_system_lzo2():
             include_dirs=[os.path.join(lzo_dir, "include")],
             libraries=['lzo2'] if _use_system_lzo else [],
             library_dirs=[os.path.join(lzo_dir, "lib")],
+            define_macros=[("MODULE_VERSION", '"%s"' % _package_version)],
             #extra_link_args=["-flat_namespace"] if sys.platform == "darwin" else [],
         )
     ],