diff --git a/libchewing/Dockerfile b/libchewing/Dockerfile
index bc52b667b..2e80438ea 100644
--- a/libchewing/Dockerfile
+++ b/libchewing/Dockerfile
@@ -18,4 +18,6 @@ FROM ossfuzz/base-libfuzzer
 MAINTAINER kcwu@csie.org
 RUN apt-get install -y make autoconf automake libtool texinfo
 
+ENV GIT_URL="https://github.com/chewing/libchewing.git"
+
 COPY build.sh chewing_fuzzer.c /src/