diff --git a/server/server.Dockerfile b/server/server.Dockerfile
index 2cc494c..1128d47 100644
--- a/server/server.Dockerfile
+++ b/server/server.Dockerfile
@@ -5,7 +5,7 @@ WORKDIR /
 
 # Copy lean files
 COPY GameServer ./GameServer
-COPY Main ./Main
+COPY Main.lean ./Main
 COPY lakefile.lean ./lakefile.lean
 COPY lake-manifest.lean ./lake-manifest.lean
 COPY lean-toolchain ./lean-toolchain