diff --git a/Dockerfile b/Dockerfile
index 426782d9920c9071cdc1022980346f029809208e..3dc55aa25859496cd7819af288344059705acfd4 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,3 +1,3 @@
 FROM ubuntu:19.04
 
-RUN ln -fs /usr/share/zoneinfo/Europe/Berlin /etc/localtime && apt-get update -qq && apt-get install -y -qq --no-install-recommends gcc libc6-dev make git bison flex tcl cmake gcc-arm-linux-gnueabihf libc6-dev-armhf-cross gcc-mingw-w64-x86-64 binutils-mingw-w64-x86-64
+RUN ln -fs /usr/share/zoneinfo/Europe/Berlin /etc/localtime && apt-get update -qq && apt-get install -y -qq --no-install-recommends gcc libc6-dev make git ca-certificates bison flex tcl cmake gcc-arm-linux-gnueabihf libc6-dev-armhf-cross gcc-mingw-w64-x86-64 binutils-mingw-w64-x86-64