diff --git a/MDK-ARM/LWIP.uvguix.29643 b/MDK-ARM/LWIP.uvguix.29643
index 15837f0..9851d69 100644
--- a/MDK-ARM/LWIP.uvguix.29643
+++ b/MDK-ARM/LWIP.uvguix.29643
@@ -3697,7 +3697,7 @@
       <Doc>
         <Name>..\usersrc\zport.c</Name>
         <ColumnNumber>0</ColumnNumber>
-        <TopLine>68</TopLine>
+        <TopLine>69</TopLine>
         <CurrentLine>102</CurrentLine>
         <Folding>1</Folding>
         <ContractedFolders></ContractedFolders>
diff --git a/usersrc/zport.c b/usersrc/zport.c
index a837c58..f03cc94 100644
--- a/usersrc/zport.c
+++ b/usersrc/zport.c
@@ -87,7 +87,8 @@ void sys_critical_enter(void)
 {
   if (g_port_exit_critical_count == 0)
   {
-    __disable_irq();
+    // __disable_irq();
+    HAL_NVIC_DisableIRQ(USART1_IRQn);
   }
   g_port_exit_critical_count++;
 }
@@ -96,6 +97,7 @@ void sys_critical_exit(void)
   g_port_exit_critical_count--;
   if (g_port_exit_critical_count == 0)
   {
-    __enable_irq();
+    // __enable_irq();
+    HAL_NVIC_EnableIRQ(USART1_IRQn);
   }
 }