diff --git a/cleanthesis.sty b/cleanthesis.sty
index eb6a3df..320ec27 100644
--- a/cleanthesis.sty
+++ b/cleanthesis.sty
@@ -103,7 +103,7 @@
 
 % OPTION bibsys
 % --> values = biber|bibtex
-\define@choicekey*[ct]{cthesis}{bibsys}[\val\colorizenr]{biber,bibtex}[bibtex]{\def\cthesis@bibsys{#1}}
+\define@choicekey*[ct]{cthesis}{bibsys}[\val\bibsysnr]{biber,bibtex}[bibtex]{\def\cthesis@bibsys{#1}}
 \setkeys[ct]{cthesis}{bibsys=bibtex}
 
 \DeclareOptionX*{