diff --git a/config/targets/CNC/grblHAL/index.js b/config/targets/CNC/grblHAL/index.js
index 2b03434d..33dedb4b 100644
--- a/config/targets/CNC/grblHAL/index.js
+++ b/config/targets/CNC/grblHAL/index.js
@@ -299,6 +299,7 @@ const commandsQuery = (req, res, SendWS) => {
                 "$133=300.000\n" +
                 "$134=300.000\n" +
                 "$135=300.000\n" +
+                "$337=\n" +
                 "ok\n"
         )
         res.send("")
diff --git a/dist/CNC/GRBLHal/index.html.gz b/dist/CNC/GRBLHal/index.html.gz
index 7c7f706f..b26c6ece 100644
Binary files a/dist/CNC/GRBLHal/index.html.gz and b/dist/CNC/GRBLHal/index.html.gz differ
diff --git a/src/targets/CNC/grblHAL/MachineSettings.js b/src/targets/CNC/grblHAL/MachineSettings.js
index 9a373720..b03bb8b0 100644
--- a/src/targets/CNC/grblHAL/MachineSettings.js
+++ b/src/targets/CNC/grblHAL/MachineSettings.js
@@ -143,7 +143,10 @@ const MachineSettings = () => {
             } else {
                 fieldData.hasmodified = true
             }
-            if (fieldData.value.trim().length == 0) validation.valid = false
+            //$337  is optionnal setting, so it can be empty
+            if (fieldData.value.trim().length == 0 && fieldData.cmd != "$337"){
+                 validation.valid = false
+            }
         }
         if (!validation.valid) {
             validation.message = T("S42")