diff --git a/applications/oracle-weblogic/10.3.6.0-2017/Dockerfile b/applications/oracle-weblogic/10.3.6.0-2017/Dockerfile
index 79e7db5..6c37b5e 100644
--- a/applications/oracle-weblogic/10.3.6.0-2017/Dockerfile
+++ b/applications/oracle-weblogic/10.3.6.0-2017/Dockerfile
@@ -12,7 +12,7 @@ RUN ( \
     if [ $? = 100 ]; then sed -i "s/security\|archive/old-releases/" /etc/apt/sources.list && apt-get update; fi \
     ) \
     && if [ "$UPDATED" = true ]; then apt-get upgrade -y; fi \
-    && apt-get install -y openssh-server \
+    && apt-get install --no-install-recommends -y openssh-server \
     && rm -rf /var/lib/apt/lists/* \
     && useradd demo \
     && echo "demo:demo" | chpasswd \
diff --git a/operating_systems/debian/Dockerfile b/operating_systems/debian/Dockerfile
index 70496bd..710d6a7 100644
--- a/operating_systems/debian/Dockerfile
+++ b/operating_systems/debian/Dockerfile
@@ -8,7 +8,8 @@ ENV DEBIAN_FRONTEND=noninteractive
 RUN apt-get update \
     && if [ "$UPDATED" = true ]; then apt-get upgrade -y; fi \
     && if [ $(cut -d "." -f 1 /etc/debian_version) -lt 4 ]; then apt-get install -y ssh; \
-    else apt-get install -y openssh-server; fi \
+    elif [ $(cut -d "." -f 1 /etc/debian_version) -eq 4 ]; then apt-get install -y openssh-server; \
+    else apt-get install --no-install-recommends -y openssh-server; fi \
     && rm -rf /var/lib/apt/lists/* \
     && useradd demo \
     && echo "demo:demo" | chpasswd \
@@ -16,4 +17,4 @@ RUN apt-get update \
 
 CMD [ "/usr/sbin/sshd", "-D" ]
 
-EXPOSE 22
\ No newline at end of file
+EXPOSE 22
diff --git a/operating_systems/ubuntu/Dockerfile b/operating_systems/ubuntu/Dockerfile
index 1a1f4e0..cfbf76c 100644
--- a/operating_systems/ubuntu/Dockerfile
+++ b/operating_systems/ubuntu/Dockerfile
@@ -12,7 +12,7 @@ RUN ( \
     if [ $? = 100 ]; then sed -i "s/security\|archive/old-releases/" /etc/apt/sources.list && apt-get update; fi \
     ) \
     && if [ "$UPDATED" = true ]; then apt-get upgrade -y; fi \
-    && apt-get install -y openssh-server \
+    && apt-get install --no-install-recommends -y openssh-server \
     && rm -rf /var/lib/apt/lists/* \
     && useradd demo \
     && echo "demo:demo" | chpasswd \