diff --git a/src/Display/Display.h b/src/Display/Display.h
index 56a9d8e..be686b0 100644
--- a/src/Display/Display.h
+++ b/src/Display/Display.h
@@ -1,7 +1,7 @@
 #ifndef _AIR_GRADIENT_OLED_H_
 #define _AIR_GRADIENT_OLED_H_
 
-#include "../main/BoardDef.h"
+#include "../Main/BoardDef.h"
 #include <Arduino.h>
 #include <Wire.h>
 
diff --git a/src/S8/S8.h b/src/S8/S8.h
index 5d18952..8624945 100644
--- a/src/S8/S8.h
+++ b/src/S8/S8.h
@@ -1,7 +1,7 @@
 #ifndef _S8_H_
 #define _S8_H_
 
-#include "../main/BoardDef.h"
+#include "../Main/BoardDef.h"
 #include "Arduino.h"
 
 /**
diff --git a/src/Sgp41/Sgp41.h b/src/Sgp41/Sgp41.h
index 5c58de1..594346e 100644
--- a/src/Sgp41/Sgp41.h
+++ b/src/Sgp41/Sgp41.h
@@ -1,7 +1,7 @@
 #ifndef _AIR_GRADIENT_SGP4X_H_
 #define _AIR_GRADIENT_SGP4X_H_
 
-#include "../main/BoardDef.h"
+#include "../Main/BoardDef.h"
 #include <Arduino.h>
 #include <Wire.h>
 
diff --git a/src/Sht/Sht.h b/src/Sht/Sht.h
index 6a9e9e1..a999b6f 100644
--- a/src/Sht/Sht.h
+++ b/src/Sht/Sht.h
@@ -1,7 +1,7 @@
 #ifndef _SHT_H_
 #define _SHT_H_
 
-#include "../main/BoardDef.h"
+#include "../Main/BoardDef.h"
 #include <Arduino.h>
 #include <Wire.h>