diff --git a/Dockerfile b/Dockerfile
index 732bde9..f438a47 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -69,6 +69,7 @@ RUN echo "#!/bin/sh\nexit 0" > /usr/sbin/policy-rc.d && \
         unixodbc-dev \
         unzip \
         xvfb \
+        xxd \
         zlib1g && \
     if [  $(ls -l /usr/share/fonts/truetype/msttcorefonts | wc -l) -ne 61 ]; \
         then echo 'msttcorefonts failed to download'; exit 1; fi  && \
diff --git a/run-document-server.sh b/run-document-server.sh
index ddce1bd..e1b8f50 100644
--- a/run-document-server.sh
+++ b/run-document-server.sh
@@ -403,7 +403,7 @@ update_ds_settings(){
 
   [ ! -f "${WOPI_PRIVATE_KEY}" ] && echo -n "Generating WOPI private key..." && openssl genpkey -algorithm RSA -outform PEM -out "${WOPI_PRIVATE_KEY}" >/dev/null 2>&1 && echo "Done"
   [ ! -f "${WOPI_PUBLIC_KEY}" ] && echo -n "Generating WOPI public key..." && openssl rsa -RSAPublicKey_out -in "${WOPI_PRIVATE_KEY}" -outform "MS PUBLICKEYBLOB" -out "${WOPI_PUBLIC_KEY}" >/dev/null 2>&1  && echo "Done"
-  WOPI_MODULUS=$(openssl rsa -pubin -inform "MS PUBLICKEYBLOB" -modulus -noout -in "${WOPI_PUBLIC_KEY}" | sed 's/Modulus=//')
+  WOPI_MODULUS=$(openssl rsa -pubin -inform "MS PUBLICKEYBLOB" -modulus -noout -in "${WOPI_PUBLIC_KEY}" | sed 's/Modulus=//' | xxd -r -p | openssl base64 -A)
   WOPI_EXPONENT=$(openssl rsa -pubin -inform "MS PUBLICKEYBLOB" -text -noout -in "${WOPI_PUBLIC_KEY}" | grep -oP '(?<=Exponent: )\d+')
   
   ${JSON} -I -e "if(this.wopi===undefined)this.wopi={};"