diff --git a/Dockerfile b/Dockerfile
index a5b6565..2370467 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -7,7 +7,7 @@ COPY . .
 RUN make build
 
 WORKDIR /go
-RUN tar cfj go-src.tbz2 src && du -sh *
+RUN tar cfz go-src.tgz src && du -sh *
 
 # this container doesn't do anything except hold the build artifact
 # and make sure it compiles.
@@ -17,7 +17,7 @@ FROM alpine
 COPY --from=builder /go/src/git.eeqj.de/sneak/feta/feta /bin/feta
 
 # put the source in there too for safekeeping
-COPY --from=builder /go/go-src.tbz2 /usr/local/src/go-src.tbz2
+COPY --from=builder /go/go-src.tgz /usr/local/src/go-src.tgz
 
 CMD /bin/feta