diff --git a/go/tests/Dockerfile b/go/tests/Dockerfile
index 4498a03fb..5e8297862 100644
--- a/go/tests/Dockerfile
+++ b/go/tests/Dockerfile
@@ -4,6 +4,8 @@ ENV GIT_TERMINAL_PROMPT=0
 RUN apk add --no-cache git
 RUN go get golang.org/x/tools/cmd/goimports
 RUN go get github.com/01-edu/z01
+COPY --from=mkcert-ca . /usr/local/share/ca-certificates
+RUN update-ca-certificates
 COPY entrypoint.sh /usr/local/bin
 COPY . src
 RUN go install rc prog/...