Add comment to setup.py
@@ -6,6 +6,8 @@ import sys
from distutils import ccompiler
import pkgconfig
+# Note: if updating LZ4_REQUIRED_VERSION you need to update docs/install.rst as
+# well.
LZ4_REQUIRED_VERSION = '>= 1.7.5'
PY3C_REQUIRED_VERSION = '>= 1.0'
