diff --git a/Dockerfile b/Dockerfile
index c9a6644..5c47078 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -5,6 +5,8 @@ ENV DEBIAN_FRONTEND=noninteractive
 
 RUN apt-get update && apt-get -y upgrade && \
     apt-get -y install --no-install-recommends wget bc && \
+    apt-get -y install --no-install-recommends openssl && \
+    apt-get -y install --no-install-recommends procps pcregrep && \
 	rm -rf /var/lib/apt/lists/*
 
 # see also