diff --git a/thys/Regular_Algebras/ROOT b/thys/Regular_Algebras/ROOT
--- a/thys/Regular_Algebras/ROOT
+++ b/thys/Regular_Algebras/ROOT
@@ -1,13 +1,13 @@
 chapter AFP
 
 session "Regular_Algebras" (AFP) = "Kleene_Algebra" +
-  options [timeout = 900]
+  options [timeout = 900, kodkod_scala = false]
   theories
     Dioid_Power_Sum
     Regular_Algebras
     Regular_Algebra_Models
     Pratts_Counterexamples
     Regular_Algebra_Variants
   document_files
     "root.tex"
     "root.bib"