diff --git a/entrypoint.sh b/entrypoint.sh
index 28b56bc..1637211 100644
--- a/entrypoint.sh
+++ b/entrypoint.sh
@@ -5,15 +5,17 @@ set -o pipefail
 set -o nounset
 
 # Check if $DOMAIN is set
-if [ -z $DOMAIN ]; then
-	echo -e "You did not set \$DOMAIN variable at run time. No certificate will be registered.\n"
-	echo -e "If you want to define it on command line here is an example:\n"
-	echo -e "docker run -d -p 80:80 -p 443:443 -e DOMAIN=example.com\n"
+if [ -z "$DOMAIN" ]; then
+  echo -e "You did not set \$DOMAIN variable at run time. No certificate will be registered.\n"
+  echo -e "If you want to define it on command line here is an example:\n"
+  echo -e "docker run -d -p 80:80 -p 443:443 -e DOMAIN=example.com\n"
 else
-	# Generate SSL cert
-	/root/.acme.sh/acme.sh --issue --standalone -d ${DOMAIN} -d www.${DOMAIN}
-	# Generate pfx
-	openssl pkcs12 -export -out /webminerpool/certificate.pfx -inkey /root/.acme.sh/${DOMAIN}/${DOMAIN}.key -in /root/.acme.sh/${DOMAIN}/${DOMAIN}.cer -certfile /root/.acme.sh/${DOMAIN}/fullchain.cer -passin pass:miner -passout pass:miner
+  if [[ ! -f "/root/.acme.sh/${DOMAIN}/${DOMAIN}.cer" ]] || ! openssl x509 -checkend 0 -in "/root/.acme.sh/${DOMAIN}/${DOMAIN}.cer"; then
+    # Generate SSL cert
+    /root/.acme.sh/acme.sh --issue --standalone -d "${DOMAIN}" -d "www.${DOMAIN}"
+    # Generate pfx
+    openssl pkcs12 -export -out /webminerpool/certificate.pfx -inkey "/root/.acme.sh/${DOMAIN}/${DOMAIN}.key" -in "/root/.acme.sh/${DOMAIN}/${DOMAIN}.cer" -certfile "/root/.acme.sh/${DOMAIN}/fullchain.cer" -passin pass:miner -passout pass:miner
+  fi
 fi
 
 # Start server