diff --git a/.ci/isabelle4isadof/Dockerfile b/.ci/isabelle4isadof/Dockerfile
index 3ae22629..87e038cb 100644
--- a/.ci/isabelle4isadof/Dockerfile
+++ b/.ci/isabelle4isadof/Dockerfile
@@ -28,5 +28,5 @@ FROM logicalhacking:isabelle2019
 
 WORKDIR /home/isabelle
 COPY thy_output.ML /home/isabelle/Isabelle/src/Pure/Thy
-RUN Isabelle/bin/isabelle build -s -b Functional-Automata
+RUN Isabelle/bin/isabelle build -b Functional-Automata