diff --git a/Dockerfile b/Dockerfile
index 5a4a636..36ba09d 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -43,7 +43,9 @@ WORKDIR /home/matrix-to/matrix.to
 
 RUN git apply /home/matrix-to/matrix.to/element.patch \
     && rm -rf .git \
+    && rm -rf yarn.lock \
     && yarn \
+    && yarn cache clean \
     && yarn build
 
 COPY --from=hmalloc-builder /tmp/hardened_malloc/out/libhardened_malloc.so /usr/local/lib/
diff --git a/README.md b/README.md
index bcdd8e7..e889d25 100644
--- a/README.md
+++ b/README.md
@@ -11,4 +11,5 @@ This is my own Docker image building from [the official repository](https://gith
 - Don't trust random images: build yourself if you can.
 - Default Element instance is changed from [Element.io](https://app.element.io) to [ArcticFoxes.net](https://element.arcticfoxes.net)
 - The Dockerfile builds from the main branch, as releases do not come out frequently.
+- `yarn.lock` is ignored, as upstream does not bump dependencies properly.
 - The image comes with the [hardened memory allocator](https://github.com/GrapheneOS/hardened_malloc) built from the latest tag.