diff --git a/Dockerfile b/Dockerfile
index 9b2d6c5..d3bb8fc 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -9,4 +9,4 @@ RUN stack build
 COPY exercises /usr/src/app
 
 # modify next line to change the wanted exercise
-CMD ["stack", "runhaskell", "Set3bTest.hs"]
\ No newline at end of file
+CMD ["stack", "runhaskell", "Set4aTest.hs"]