diff --git a/docker/Dockerfile.alpine b/docker/Dockerfile.alpine
index 892d5539..0affec50 100644
--- a/docker/Dockerfile.alpine
+++ b/docker/Dockerfile.alpine
@@ -20,6 +20,7 @@ RUN [ "rm", "-rf", "build" ]
 FROM alpine:3.11 as runtime
 
 RUN apk add --no-cache libstdc++ mbedtls
+RUN apk add --no-cache ca-certificates
 
 RUN addgroup -S app && adduser -S -G app app
 COPY --chown=app:app --from=build /usr/local/bin/ws /usr/local/bin/ws