diff --git a/Dockerfile b/Dockerfile
index bd7ffa5..aadc6f1 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -11,7 +11,10 @@ RUN rustup target add "$TARGET"
 RUN USER=root mkdir ./itkg
 WORKDIR ./itkg
 ADD . ./
-RUN cargo build --release --locked --target "$TARGET" \
+
+# caché: xenera unha capa de docker para os sucesivos builds
+RUN --mount=type=cache,target=/usr/local/cargo/registry \
+ cargo build --release --locked --target "$TARGET" \
  && mv "target/$TARGET/release/itkg" . \
  && strip itkg