diff --git a/cyphernodeconf_docker/templates/installer/docker/docker-compose.yaml b/cyphernodeconf_docker/templates/installer/docker/docker-compose.yaml
index cddc003..f1a4bbe 100644
--- a/cyphernodeconf_docker/templates/installer/docker/docker-compose.yaml
+++ b/cyphernodeconf_docker/templates/installer/docker/docker-compose.yaml
@@ -160,6 +160,9 @@ services:
     environment:
       - "TRACING=1"
       - "OTSCLIENT_LISTENING_PORT=6666"
+      <% if (net === 'testnet') { %>
+      - "TESTNET=1"
+      <% } %>
     volumes:
       - "<%= otsclient_datapath %>:/otsfiles"
       - "<%= otsclient_datapath %>/bitcoin.conf:/.bitcoin/bitcoin.conf"
diff --git a/otsclient_docker/script/otsclient.sh b/otsclient_docker/script/otsclient.sh
index 50caaa4..66d9a09 100644
--- a/otsclient_docker/script/otsclient.sh
+++ b/otsclient_docker/script/otsclient.sh
@@ -1,5 +1,7 @@
 #!/bin/sh
 
+# There an OTS server on testnet: ots.test4mind.com
+
 . ./trace.sh
 
 stamp() {
@@ -12,9 +14,15 @@ stamp() {
   local returncode
   local data
 
-  trace "[stamp] ots-cli.js stamp -d ${hash}"
-  result=$(cd /otsfiles && ots-cli.js stamp -d ${hash} 2>&1)
-  returncode=$?
+  if [ "${TESTNET}" -eq "1" ]; then
+    trace "[stamp] ots-cli.js stamp -c \"https://ots.testnet.kexkey.com\" -d ${hash}"
+    result=$(cd /otsfiles && ots-cli.js stamp -c "https://ots.testnet.kexkey.com" -d ${hash} 2>&1)
+    returncode=$?
+  else
+    trace "[stamp] ots-cli.js stamp -d ${hash}"
+    result=$(cd /otsfiles && ots-cli.js stamp -d ${hash} 2>&1)
+    returncode=$?
+  fi
   trace_rc ${returncode}
   trace "[stamp] result=${result}"
 
@@ -51,9 +59,15 @@ upgrade() {
   local result
   local returncode
 
-  trace "[upgrade] ots-cli.js upgrade ${hash}.ots"
-  result=$(cd /otsfiles && ots-cli.js upgrade ${hash}.ots 2>&1)
-  returncode=$?
+  if [ "${TESTNET}" -eq "1" ]; then
+    trace "[upgrade] ots-cli.js -l \"https://testnet.calendar.kexkey.com/\" upgrade -c \"https://testnet.calendar.kexkey.com/\" ${hash}.ots"
+    result=$(cd /otsfiles && ots-cli.js -l "https://testnet.calendar.kexkey.com/" upgrade -c "https://testnet.calendar.kexkey.com/" ${hash}.ots 2>&1)
+    returncode=$?
+  else
+    trace "[upgrade] ots-cli.js upgrade ${hash}.ots"
+    result=$(cd /otsfiles && ots-cli.js upgrade ${hash}.ots 2>&1)
+    returncode=$?
+  fi
   trace_rc ${returncode}
   trace "[upgrade] result=${result}"
 
@@ -97,12 +111,22 @@ verify() {
   # Let's create the OTS file locally from the base64
   trace "[verify] Creating /otsfiles/otsfile-$$.ots"
   echo "${base64otsfile}" | base64 -d > /otsfiles/otsfile-$$.ots
-  trace "[verify] ots-cli.js verify -d ${hash} /otsfiles/otsfile-$$.ots"
-  result=$(ots-cli.js verify -d ${hash} /otsfiles/otsfile-$$.ots 2>&1)
-  returncode=$?
+
+  if [ "${TESTNET}" -eq "1" ]; then
+    trace "[verify] ots-cli.js -l \"https://testnet.calendar.kexkey.com/\" verify -d ${hash} /otsfiles/otsfile-$$.ots"
+    result=$(ots-cli.js -l "https://testnet.calendar.kexkey.com/" verify -d ${hash} /otsfiles/otsfile-$$.ots 2>&1)
+    returncode=$?
+  else
+    trace "[verify] ots-cli.js verify -d ${hash} /otsfiles/otsfile-$$.ots"
+    result=$(ots-cli.js verify -d ${hash} /otsfiles/otsfile-$$.ots 2>&1)
+    returncode=$?
+  fi
   trace_rc ${returncode}
   trace "[verify] result=${result}"
 
+  trace "[verify] Removing temporary file /otsfiles/otsfile-$$.ots..."
+  rm /otsfiles/otsfile-$$.ots
+
   # /script $ ots-cli.js -v v -d 7d694f669d6da235a5fb9ef8c89da55e30b59eb662a7131f85344d798fc3280c /otsfiles/Order_10019_1543447088465.ots
   # Assuming target hash is '7d694f669d6da235a5fb9ef8c89da55e30b59eb662a7131f85344d798fc3280c'
   # Success! Bitcoin block 551876 attests existence as of 2018-11-28 GMT
diff --git a/proxy_docker/app/script/ots.sh b/proxy_docker/app/script/ots.sh
index f034adf..55e94fd 100644
--- a/proxy_docker/app/script/ots.sh
+++ b/proxy_docker/app/script/ots.sh
@@ -202,14 +202,23 @@ serve_ots_backoffice() {
         url=$(echo "${row}" | cut -d '|' -f2)
         trace "[serve_ots_backoffice] url=${url}"
 
-        # Call back newly upgraded stamps
-        notify_web "${url}"
-        returncode=$?
-        trace_rc ${returncode}
+        # Call back newly upgraded stamps if url provided
+        if [ -n ${url} ]; then
+          trace "[serve_ots_backoffice] url is not empty, now trying to call it!"
 
-        # Even if curl executed ok, we need to make sure the http return code is also ok
+          notify_web "${url}"
+          returncode=$?
+          trace_rc ${returncode}
+
+          # Even if curl executed ok, we need to make sure the http return code is also ok
+
+          if [ "${returncode}" -eq "0" ]; then
+            sql "UPDATE stamp SET calledback=1 WHERE id=${id}"
+            trace_rc $?
+          fi
+        else
+          trace "[serve_ots_backoffice] url is empty, obviously won't try to call it!"
 
-        if [ "${returncode}" -eq "0" ]; then
           sql "UPDATE stamp SET calledback=1 WHERE id=${id}"
           trace_rc $?
         fi