diff --git a/README.md b/README.md
index 1d90b66d5..6388ef9d5 100644
--- a/README.md
+++ b/README.md
@@ -27,7 +27,7 @@ this is a work-in-progress chiptune tracker compatible with DefleMask modules (.
 - additional features on top:
   - SSG envelopes in Neo Geo
   - full duty/cutoff range in C64
-  - ability to change tempo mid-song with `Cxxx` effect (`xxx` between `000` and `3fff`)
+  - ability to change tempo mid-song with `Cxxx` effect (`xxx` between `000` and `3ff`)
 - open-source. GPLv2.
 
 ## downloads