diff --git a/setup.py b/setup.py
index 4ffd28c6e..e1a66fbe9 100644
--- a/setup.py
+++ b/setup.py
@@ -29,6 +29,12 @@
 # POSSIBILITY OF SUCH DAMAGE.
 ###
 
+import sys
+
+if sys.version_info < (2, 3, 0):
+    sys.stderr.write("Supybot requires Python 2.3 or newer.\n")
+    sys.exit(-1)
+
 import glob
 import os.path