diff --git a/Dockerfile.ci b/Dockerfile.ci
index 2926f03..755edef 100644
--- a/Dockerfile.ci
+++ b/Dockerfile.ci
@@ -1,4 +1,4 @@
 FROM rust:1.55
 COPY Cargo.toml .
-RUN cargo fetch
+RUN echo "fn main() {}" > ./src/main.rs && cargo fetch
 COPY src/ ./src/