diff --git a/include/REL/instDll.h b/include/REL/instDll.h
index e6e09e34..8b00303e 100644
--- a/include/REL/instDll.h
+++ b/include/REL/instDll.h
@@ -1,5 +1,5 @@
-#ifndef M401DLL_H
-#define M401DLL_H
+#ifndef INSTDLL_H
+#define INSTDLL_H
 
 #include "game/minigame_seq.h"
 
diff --git a/include/REL/m407dll.h b/include/REL/m407dll.h
index 788ede40..a5dbf0fb 100644
--- a/include/REL/m407dll.h
+++ b/include/REL/m407dll.h
@@ -1,5 +1,10 @@
+#ifndef M407DLL_H
+#define M407DLL_H
+
 #include "game/object.h"
 
 #define ARRAY_COUNT(arr) (s32)(sizeof(arr) / sizeof(arr[0]))
 
 typedef void (*ObjFuncs)(omObjData*);
+
+#endif
diff --git a/include/REL/m409Dll.h b/include/REL/m409Dll.h
index d1f5cce2..76459447 100644
--- a/include/REL/m409Dll.h
+++ b/include/REL/m409Dll.h
@@ -1,3 +1,6 @@
+#ifndef M409DLL_H
+#define M409DLL_H
+
 #include "dolphin.h"
 
 #include "game/object.h"
@@ -362,4 +365,6 @@ void fn_1_F2F8(s16, s16, u8, f32);
 void fn_1_F370(s16, f32);
 void fn_1_F408(s16, s16, u8);
 void fn_1_F478(s16, s16, u8, u8);
-void fn_1_F4F0(s16, u8);
\ No newline at end of file
+void fn_1_F4F0(s16, u8);
+
+#endif
diff --git a/include/REL/m412Dll.h b/include/REL/m412Dll.h
index aea02d47..2017123c 100644
--- a/include/REL/m412Dll.h
+++ b/include/REL/m412Dll.h
@@ -1,3 +1,6 @@
+#ifndef M412DLL_H
+#define M412DLL_H
+
 #include "dolphin.h"
 
 #include "game/object.h"
@@ -113,4 +116,6 @@ void fn_1_A618(ModelData* model, ParticleData* particle, Mtx matrix);
 //...
 void fn_1_AA88(ModelData* model, ParticleData* particle, Mtx matrix); // *
 void fn_1_B160(void); // *
-void fn_1_B1C0(void); // *
\ No newline at end of file
+void fn_1_B1C0(void); // *
+
+#endif
diff --git a/include/REL/m440Dll.h b/include/REL/m440Dll.h
index 181ce25b..071bc6a5 100644
--- a/include/REL/m440Dll.h
+++ b/include/REL/m440Dll.h
@@ -1,3 +1,6 @@
+#ifndef M440DLL_H
+#define M440DLL_H
+
 #include "dolphin/types.h"
 #include "game/hsfman.h"
 
@@ -347,3 +350,5 @@ void fn_1_F228(void);
 u16 fn_1_F4C0(unkObjStruct*, u16);
 void fn_1_F4D4(unkObjStruct*, u16, u16);
 s32 fn_1_F4FC(s32);
+
+#endif
diff --git a/include/REL/m446Dll.h b/include/REL/m446Dll.h
index fc1e35ba..1f5a4c6a 100644
--- a/include/REL/m446Dll.h
+++ b/include/REL/m446Dll.h
@@ -1,3 +1,6 @@
+#ifndef M446DLL_H
+#define M446DLL_H
+
 #include "dolphin/types.h"
 
 #include "game/process.h"
@@ -302,3 +305,5 @@ void fn_1_83F0(unkStruct9*);
 void fn_1_84AC(unkStruct9*);
 void fn_1_852C(unkStruct9*);
 void fn_1_860C(unkStruct9*);
+
+#endif
diff --git a/include/REL/w03Dll.h b/include/REL/w03Dll.h
index 36e741d7..022b6894 100644
--- a/include/REL/w03Dll.h
+++ b/include/REL/w03Dll.h
@@ -1,3 +1,6 @@
+#ifndef REL_W03_H
+#define REL_W03_H
+
 #include "game/gamework_data.h"
 #include "dolphin.h"
 #include "REL/executor.h"
@@ -27,3 +30,5 @@ typedef struct w03State {
 
 extern w03State* lbl_1_bss_0;
 extern s16 lbl_1_bss_C[MAPOBJ_MAX];
+
+#endif
diff --git a/include/REL/w05Dll.h b/include/REL/w05Dll.h
index a326cb65..be7b49db 100644
--- a/include/REL/w05Dll.h
+++ b/include/REL/w05Dll.h
@@ -1,3 +1,6 @@
+#ifndef REL_W05_H
+#define REL_W05_H
+
 #include "dolphin/types.h"
 
 #include "game/board/main.h"
@@ -222,3 +225,5 @@ extern s32* lbl_1_bss_10;
 extern s16 lbl_1_bss_8[4];
 extern Process* lbl_1_bss_4;
 extern bitcopy* lbl_1_bss_0;
+
+#endif
diff --git a/include/REL/w10Dll.h b/include/REL/w10Dll.h
index f5144a93..93342461 100644
--- a/include/REL/w10Dll.h
+++ b/include/REL/w10Dll.h
@@ -1,3 +1,6 @@
+#ifndef REL_W10_H
+#define REL_W10_H
+
 #include "game/gamework_data.h"
 #include "dolphin.h"
 #include "REL/executor.h"
@@ -86,4 +89,6 @@ extern s16 tutorialExitWin;
 extern s16 boardStarHostMdl;
 extern s16 boardShopHostMdl;
 extern s16 boardLotteryHostMdl;
-extern s16 boardBooHouseHostMdl;
\ No newline at end of file
+extern s16 boardBooHouseHostMdl;
+
+#endif
diff --git a/include/msm/msmmem.h b/include/msm/msmmem.h
index 7deab41a..ca14b0c9 100644
--- a/include/msm/msmmem.h
+++ b/include/msm/msmmem.h
@@ -1,5 +1,10 @@
+#ifndef MSMMEM_H
+#define MSMMEM_H
+
 #include "dolphin/types.h"
 
 void msmMemFree(void*);
 void* msmMemAlloc(s32);
-void msmMemInit(void*, u32);
\ No newline at end of file
+void msmMemInit(void*, u32);
+
+#endif