diff --git a/src/main/io/serial.c b/src/main/io/serial.c
index 7493f51d2e..e9e9a47122 100644
--- a/src/main/io/serial.c
+++ b/src/main/io/serial.c
@@ -76,13 +76,14 @@ static serialPortFunction_t serialPortFunctions[SERIAL_PORT_COUNT] = {
 #ifdef USE_VCP
     {SERIAL_PORT_USB_VCP,     NULL, SCENARIO_UNUSED, FUNCTION_NONE},
 #endif
+#ifdef USE_USART1
     {SERIAL_PORT_USART1,      NULL, SCENARIO_UNUSED, FUNCTION_NONE},
-    {SERIAL_PORT_USART2,      NULL, SCENARIO_UNUSED, FUNCTION_NONE},
-#if (SERIAL_PORT_COUNT > 3)
-    {SERIAL_PORT_USART3,      NULL, SCENARIO_UNUSED, FUNCTION_NONE},
-#if (SERIAL_PORT_COUNT > 4)
-    {SERIAL_PORT_USART4,      NULL, SCENARIO_UNUSED, FUNCTION_NONE}
 #endif
+#ifdef USE_USART2
+    {SERIAL_PORT_USART2,      NULL, SCENARIO_UNUSED, FUNCTION_NONE},
+#endif
+#ifdef USE_USART3
+    {SERIAL_PORT_USART3,      NULL, SCENARIO_UNUSED, FUNCTION_NONE},
 #endif
 };
 
@@ -90,13 +91,14 @@ const serialPortConstraint_t serialPortConstraints[SERIAL_PORT_COUNT] = {
 #ifdef USE_VCP
     {SERIAL_PORT_USB_VCP,       9600,   115200,   SPF_NONE },
 #endif
+#ifdef USE_USART1
     {SERIAL_PORT_USART1,        9600,   115200,   SPF_NONE | SPF_SUPPORTS_SBUS_MODE | SPF_SUPPORTS_BIDIR_MODE},
-    {SERIAL_PORT_USART2,        9600,   115200,   SPF_SUPPORTS_CALLBACK | SPF_SUPPORTS_SBUS_MODE | SPF_SUPPORTS_BIDIR_MODE},
-#if (SERIAL_PORT_COUNT > 3)
-    {SERIAL_PORT_USART3,        9600,   115200,   SPF_SUPPORTS_CALLBACK | SPF_SUPPORTS_SBUS_MODE | SPF_SUPPORTS_BIDIR_MODE},
-#if (SERIAL_PORT_COUNT > 4)
-    {SERIAL_PORT_USART4,        9600,   115200,   SPF_SUPPORTS_CALLBACK}
 #endif
+#ifdef USE_USART2
+    {SERIAL_PORT_USART2,        9600,   115200,   SPF_SUPPORTS_CALLBACK | SPF_SUPPORTS_SBUS_MODE | SPF_SUPPORTS_BIDIR_MODE},
+#endif
+#ifdef USE_USART3
+    {SERIAL_PORT_USART3,        9600,   115200,   SPF_SUPPORTS_CALLBACK | SPF_SUPPORTS_SBUS_MODE | SPF_SUPPORTS_BIDIR_MODE},
 #endif
 };