diff --git a/README.md b/README.md
index 21cbd45..d545a4e 100644
--- a/README.md
+++ b/README.md
@@ -247,7 +247,11 @@ If you'd like to contribute, there's a submodule called `chembl_downloader.queri
 where you can add a useful SQL queries along with a description of what it does for easy
 importing and reuse.
 
-## Statistics
+## Statistics and Compatibility
+
+`chembl-downloader` is compatible with all versions of ChEMBL. However, some files are
+not available for all versions. For example, the SQLite version of the database was first
+added in release 21 (2015-02-12).
 
 |   ChEMBL Version | Release Date   |
 |------------------|----------------|