diff --git a/run.sh b/run.sh
index b4a22e1..faae2c4 100755
--- a/run.sh
+++ b/run.sh
@@ -14,6 +14,7 @@ fi
 
 mkdir -p /static
 cp -f "${CA_CERT_FILE}" /static/ca.crt
+openssl x509 -in "${CA_CERT_FILE}" -outform DER -out /static/ca.der
 
 [ -d "${CERTS_DIR}/ssl_db" ] || /usr/lib/squid/security_file_certgen -c \
     -s "${CERTS_DIR}/ssl_db" -M 4MB