diff --git a/Dockerfile b/Dockerfile
index 14beddc5945282682136e0a9d326fc24cac9fa18..f5ca3cbc4456cdd5494bf9dd0be1f1c90a3eee02 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -13,7 +13,7 @@ RUN apt-get update \
  && rm -rf /usr/share/doc/* /usr/share/locales/* /usr/share/man/* \
  && rm -rf /var/lib/apt/lists/*
 
-RUN curl https://packages.icinga.com/icinga.key | apt-key add - \
+RUN curl -k https://packages.icinga.com/icinga.key | apt-key add - \
  && DIST=$(awk -F"[)(]+" '/VERSION=/ {print $2}' /etc/os-release) \
  && DIST=buster \
  && echo "deb http://packages.icinga.com/raspbian icinga-${DIST} main" > /etc/apt/sources.list.d/${DIST}-icinga.list