diff --git a/include/kabufuda/AsyncIO.hpp b/include/kabufuda/AsyncIO.hpp
index 07b5f8e..33923d2 100644
--- a/include/kabufuda/AsyncIO.hpp
+++ b/include/kabufuda/AsyncIO.hpp
@@ -1,5 +1,4 @@
-#ifndef __KABU_ASYNCIO_HPP__
-#define __KABU_ASYNCIO_HPP__
+#pragma once
 
 #ifndef _WIN32
 #include <aio.h>
@@ -49,4 +48,3 @@ public:
 
 }
 
-#endif // __KABU_ASYNCIO_HPP__
diff --git a/include/kabufuda/BlockAllocationTable.hpp b/include/kabufuda/BlockAllocationTable.hpp
index 5796850..cc9eaca 100644
--- a/include/kabufuda/BlockAllocationTable.hpp
+++ b/include/kabufuda/BlockAllocationTable.hpp
@@ -1,5 +1,4 @@
-#ifndef __KABU_BLOCKALLOCATIONATABLE_HPP__
-#define __KABU_BLOCKALLOCATIONATABLE_HPP__
+#pragma once
 
 #include "Constants.hpp"
 
@@ -39,4 +38,3 @@ public:
     uint16_t numFreeBlocks() const { return m_freeBlocks; }
 };
 }
-#endif // __KABU_BLOCKALLOCATIONATABLE_HPP__
diff --git a/include/kabufuda/Card.hpp b/include/kabufuda/Card.hpp
index c88714d..aa8d56e 100644
--- a/include/kabufuda/Card.hpp
+++ b/include/kabufuda/Card.hpp
@@ -1,5 +1,4 @@
-#ifndef __KABU_CARD_HPP__
-#define __KABU_CARD_HPP__
+#pragma once
 
 #include "BlockAllocationTable.hpp"
 #include "Directory.hpp"
@@ -438,4 +437,3 @@ public:
 };
 }
 
-#endif // __CARD_HPP__
diff --git a/include/kabufuda/Constants.hpp b/include/kabufuda/Constants.hpp
index 730dc88..f7f6fee 100644
--- a/include/kabufuda/Constants.hpp
+++ b/include/kabufuda/Constants.hpp
@@ -1,5 +1,4 @@
-#ifndef __KABU_CONSTANTS_HPP__
-#define __KABU_CONSTANTS_HPP__
+#pragma once
 
 #include <stdint.h>
 #include "Util.hpp"
@@ -90,4 +89,3 @@ enum class EEncoding : uint16_t
 };
 }
 
-#endif // __KABU_CONSTANTS_HPP__
diff --git a/include/kabufuda/Directory.hpp b/include/kabufuda/Directory.hpp
index 4771436..b4073f5 100644
--- a/include/kabufuda/Directory.hpp
+++ b/include/kabufuda/Directory.hpp
@@ -1,5 +1,4 @@
-#ifndef __KABU_DIRECTORY_HPP__
-#define __KABU_DIRECTORY_HPP__
+#pragma once
 
 #include "File.hpp"
 
@@ -41,4 +40,3 @@ public:
 };
 }
 
-#endif // __KABU_DIRECTORY_HPP__
diff --git a/include/kabufuda/File.hpp b/include/kabufuda/File.hpp
index e5bc721..f20852e 100644
--- a/include/kabufuda/File.hpp
+++ b/include/kabufuda/File.hpp
@@ -1,5 +1,4 @@
-#ifndef __KABU_FILE_HPP__
-#define __KABU_FILE_HPP__
+#pragma once
 
 #include "Constants.hpp"
 
@@ -44,4 +43,3 @@ public:
 };
 }
 
-#endif // __KABU_FILE_HPP__
diff --git a/include/kabufuda/SRAM.hpp b/include/kabufuda/SRAM.hpp
index e6c4566..da622e5 100644
--- a/include/kabufuda/SRAM.hpp
+++ b/include/kabufuda/SRAM.hpp
@@ -1,5 +1,4 @@
-#ifndef SRAM_HPP
-#define SRAM_HPP
+#pragma once
 
 #include <stdint.h>
 
@@ -73,4 +72,3 @@ union SRAM
 extern const SRAM g_SRAM;
 }
 
-#endif // SRAM_HPP
diff --git a/include/kabufuda/Util.hpp b/include/kabufuda/Util.hpp
index b1ef901..406e0f5 100644
--- a/include/kabufuda/Util.hpp
+++ b/include/kabufuda/Util.hpp
@@ -1,5 +1,4 @@
-#ifndef __KABU_UTIL_HPP__
-#define __KABU_UTIL_HPP__
+#pragma once
 
 #ifndef _WIN32
 #include <cstdlib>
@@ -306,4 +305,3 @@ enum class ECardResult
 };
 }
 
-#endif // __KABU_UTIL_HPP__
diff --git a/include/kabufuda/WideStringConvert.hpp b/include/kabufuda/WideStringConvert.hpp
index 795fcc2..af1436e 100644
--- a/include/kabufuda/WideStringConvert.hpp
+++ b/include/kabufuda/WideStringConvert.hpp
@@ -1,5 +1,4 @@
-#ifndef __KABU_WIDESTRINGCONVERT_HPP__
-#define __KABU_WIDESTRINGCONVERT_HPP__
+#pragma once
 
 #include <string>
 
@@ -9,4 +8,3 @@ std::string WideToUTF8(std::wstring_view src);
 std::wstring UTF8ToWide(std::string_view src);
 }
 
-#endif // __KABU_WIDESTRINGCONVERT_HPP__
diff --git a/include/kabufuda/winsupport.hpp b/include/kabufuda/winsupport.hpp
index 1371532..d40ada7 100644
--- a/include/kabufuda/winsupport.hpp
+++ b/include/kabufuda/winsupport.hpp
@@ -1,5 +1,4 @@
-#ifndef _HECL_WINSUPPORT_H_
-#define _HECL_WINSUPPORT_H_
+#pragma once
 
 #ifndef WIN32_LEAN_AND_MEAN
 #define WIN32_LEAN_AND_MEAN 1
@@ -11,4 +10,3 @@
 
 void* memmem(const void *haystack, size_t hlen, const void *needle, size_t nlen);
 
-#endif // _HECL_WINSUPPORT_H_