diff --git a/src/manufacturingcommands.cpp b/src/manufacturingcommands.cpp
index 50c91b9..e395e8c 100644
--- a/src/manufacturingcommands.cpp
+++ b/src/manufacturingcommands.cpp
@@ -587,6 +587,25 @@
     return ipmi::response(resetMtmTimer(yield));
 }
 
+ipmi::Cc mfgFilterMessage(ipmi::message::Request::ptr request)
+{
+    // i2c master write read command needs additional checking
+    if ((request->ctx->netFn == ipmi::netFnApp) &&
+        (request->ctx->cmd == ipmi::app::cmdMasterWriteRead))
+    {
+        if (request->payload.size() > 4)
+        {
+            // Allow write data count > 1, only if it is in MFG mode
+            if (mtm.getAccessLvl() != MtmLvl::mtmAvailable)
+            {
+                return ipmi::ccInsufficientPrivilege;
+            }
+        }
+    }
+
+    return ipmi::ccSuccess;
+}
+
 } // namespace ipmi
 
 void register_mtm_commands() __attribute__((constructor));
@@ -608,5 +627,10 @@
         static_cast<ipmi::Cmd>(IPMINetfnIntelOEMGeneralCmd::cmdMtmKeepAlive),
         ipmi::Privilege::Admin, ipmi::mtmKeepAlive);
 
+    ipmi::registerFilter(ipmi::netFnOemOne,
+                         [](ipmi::message::Request::ptr request) {
+                             return ipmi::mfgFilterMessage(request);
+                         });
+
     return;
 }