diff --git a/include/s/README.txt b/include/s/README.txt
index 99281a97..5be519ee 100644
--- a/include/s/README.txt
+++ b/include/s/README.txt
@@ -5,7 +5,8 @@ with differences/modifications outlined below:
 
 The NSMBW code uses inlined destructors. In SS, these destructors are all part of the s_StateID.cpp(?) TU,
 and pretty much every generic instantiation of the state manager (which for a large part are in RELs)
-will call back into those destructors in the main DOL.
+will call back into those destructors in the main DOL. As a result, the destructors were made not inline
+and explicitly instantiated in s_StateID.cpp
 
 ## s_StateIDChk.hpp
 
diff --git a/include/s/docgroup.h b/include/s/docgroup.h
index a99aa2fb..43c81fd9 100644
--- a/include/s/docgroup.h
+++ b/include/s/docgroup.h
@@ -1,4 +1,6 @@
-#pragma once
+#ifndef S_DOCGROUP_H
+#define S_DOCGROUP_H
+
 // [This header file defines documentation groups for better categorization]
 
 /// @ingroup game
@@ -8,3 +10,5 @@
 /// @defgroup state sState
 /// @ingroup slib
 /// @brief A state system implementation.
+
+#endif
diff --git a/include/s/s_FState.hpp b/include/s/s_FState.hpp
index a883d6f3..5ce14991 100644
--- a/include/s/s_FState.hpp
+++ b/include/s/s_FState.hpp
@@ -1,4 +1,6 @@
-#pragma once
+#ifndef S_FSTATE_H
+#define S_FSTATE_H
+
 #include <s/s_StateInterfaces.hpp>
 #include <s/s_FStateID.hpp>
 
@@ -42,3 +44,5 @@ private:
     T &mpOwner; ///< The owner of this state.
     const sFStateID_c<T> *mpID; ///< The state ID that runs the state methods.
 };
+
+#endif
diff --git a/include/s/s_FStateFct.hpp b/include/s/s_FStateFct.hpp
index 3d349d3e..cb488d2d 100644
--- a/include/s/s_FStateFct.hpp
+++ b/include/s/s_FStateFct.hpp
@@ -1,4 +1,6 @@
-#pragma once
+#ifndef S_FSTATEFCT_H
+#define S_FSTATEFCT_H
+
 #include <s/s_StateInterfaces.hpp>
 #include <s/s_FState.hpp>
 #include <s/s_StateID.hpp>
@@ -27,3 +29,5 @@ public:
 private:
     sFState_c<T> mState;
 };
+
+#endif
diff --git a/include/s/s_FStateID.hpp b/include/s/s_FStateID.hpp
index 7ea2295a..5fd05476 100644
--- a/include/s/s_FStateID.hpp
+++ b/include/s/s_FStateID.hpp
@@ -1,4 +1,6 @@
-#pragma once
+#ifndef S_FSTATEID_H
+#define S_FSTATEID_H
+
 #include <s/s_StateID.hpp>
 #include <MSL_C/string.h>
 
@@ -59,3 +61,5 @@ private:
     stateFunc mpExecute; ///< The execute method for this state ID.
     stateFunc mpFinalize; ///< The finalize method for this state ID.
 };
+
+#endif
diff --git a/include/s/s_FStateMgr.hpp b/include/s/s_FStateMgr.hpp
index f154cbb6..a001ffea 100644
--- a/include/s/s_FStateMgr.hpp
+++ b/include/s/s_FStateMgr.hpp
@@ -1,4 +1,6 @@
-#pragma once
+#ifndef S_FSTATEMGR_H
+#define S_FSTATEMGR_H
+
 #include <s/s_FStateID.hpp>
 #include <s/s_StateMgr.hpp>
 #include <s/s_FState.hpp>
@@ -18,3 +20,5 @@ public:
     sFStateMgr_c(T &owner, const sStateIDIf_c &initializeState) :
         sStateMgr_c<T, Method, sFStateFct_c, sStateIDChk_c>(owner, initializeState) {}
 };
+
+#endif
diff --git a/include/s/s_Phase.hpp b/include/s/s_Phase.hpp
index 4b3d6403..596484b6 100644
--- a/include/s/s_Phase.hpp
+++ b/include/s/s_Phase.hpp
@@ -1,4 +1,5 @@
-#pragma once
+#ifndef S_PHASE_H
+#define S_PHASE_H
 
 // Note: Ported from https://github.com/NSMBW-Community/NSMBW-Decomp/tree/master/include/dol/sLib
 // See include/s/README.txt for changes made
@@ -35,3 +36,5 @@ public:
     unsigned short mPhaseLength; ///< The length of the method list.
     unsigned short mCurrMethod; ///< The index of the method to execute.
 };
+
+#endif
diff --git a/include/s/s_State.hpp b/include/s/s_State.hpp
index 8a7079f9..97a5847e 100644
--- a/include/s/s_State.hpp
+++ b/include/s/s_State.hpp
@@ -1,4 +1,6 @@
-#pragma once
+#ifndef S_STATE_H
+#define S_STATE_H
+
 #include <s/s_FStateMgr.hpp>
 #include <s/s_StateMethodUsr_FI.hpp>
 
@@ -15,3 +17,5 @@
     &class::initializeState_##name, \
     &class::executeState_##name, \
     &class::finalizeState_##name)
+
+#endif
diff --git a/include/s/s_StateID.hpp b/include/s/s_StateID.hpp
index e74d155e..422d9143 100644
--- a/include/s/s_StateID.hpp
+++ b/include/s/s_StateID.hpp
@@ -1,4 +1,6 @@
-#pragma once
+#ifndef S_STATEID_H
+#define S_STATEID_H
+
 #include <s/s_StateInterfaces.hpp>
 
 // Note: Ported from https://github.com/NSMBW-Community/NSMBW-Decomp/tree/master/include/dol/sLib
@@ -44,3 +46,5 @@ namespace sStateID {
     /// @ingroup state
     extern sStateID_c null; ///< A null state instance.
 }
+
+#endif
diff --git a/include/s/s_StateIDChk.hpp b/include/s/s_StateIDChk.hpp
index c808ad8b..5237cbaf 100644
--- a/include/s/s_StateIDChk.hpp
+++ b/include/s/s_StateIDChk.hpp
@@ -1,4 +1,6 @@
-#pragma once
+#ifndef S_STATEIDCHK_H
+#define S_STATEIDCHK_H
+
 #include <s/s_StateInterfaces.hpp>
 
 // Note: Ported from https://github.com/NSMBW-Community/NSMBW-Decomp/tree/master/include/dol/sLib
@@ -11,3 +13,5 @@ public:
     virtual ~sStateIDChk_c();
     virtual bool isNormalID(const sStateIDIf_c &) const { return true; }
 };
+
+#endif
diff --git a/include/s/s_StateInterfaces.hpp b/include/s/s_StateInterfaces.hpp
index 0acd6f80..8e28f44c 100644
--- a/include/s/s_StateInterfaces.hpp
+++ b/include/s/s_StateInterfaces.hpp
@@ -1,4 +1,5 @@
-#pragma once
+#ifndef S_STATEINTERFACES_H
+#define S_STATEINTERFACES_H
 
 // Note: Ported from https://github.com/NSMBW-Community/NSMBW-Decomp/tree/master/include/dol/sLib
 // See include/s/README.txt for changes made
@@ -74,3 +75,5 @@ public:
 };
 
 /// @}
+
+#endif
diff --git a/include/s/s_StateMethod.hpp b/include/s/s_StateMethod.hpp
index 4feb0c6a..4d7b630d 100644
--- a/include/s/s_StateMethod.hpp
+++ b/include/s/s_StateMethod.hpp
@@ -1,4 +1,6 @@
-#pragma once
+#ifndef S_STATEMETHOD_H
+#define S_STATEMETHOD_H
+
 #include <s/s_StateInterfaces.hpp>
 
 // Note: Ported from https://github.com/NSMBW-Community/NSMBW-Decomp/tree/master/include/dol/sLib
@@ -50,3 +52,5 @@ protected:
 
     sStateIf_c *mpState; ///< The current state holder.
 };
+
+#endif
diff --git a/include/s/s_StateMethodUsr_FI.hpp b/include/s/s_StateMethodUsr_FI.hpp
index 8104557f..a18516df 100644
--- a/include/s/s_StateMethodUsr_FI.hpp
+++ b/include/s/s_StateMethodUsr_FI.hpp
@@ -1,4 +1,6 @@
-#pragma once
+#ifndef S_STATEMETHODUSR_FI_H
+#define S_STATEMETHODUSR_FI_H
+
 #include <s/s_StateMethod.hpp>
 
 // Note: Ported from https://github.com/NSMBW-Community/NSMBW-Decomp/tree/master/include/dol/sLib
@@ -17,3 +19,5 @@ public:
     virtual void finalizeStateLocalMethod();
     virtual void changeStateLocalMethod(const sStateIDIf_c &newStateID);
 };
+
+#endif
diff --git a/include/s/s_StateMgr.hpp b/include/s/s_StateMgr.hpp
index 66d07020..c043eb71 100644
--- a/include/s/s_StateMgr.hpp
+++ b/include/s/s_StateMgr.hpp
@@ -1,4 +1,6 @@
-#pragma once
+#ifndef S_STATEMGR_H
+#define S_STATEMGR_H
+
 #include <s/s_StateInterfaces.hpp>
 
 // Note: Ported from https://github.com/NSMBW-Community/NSMBW-Decomp/tree/master/include/dol/sLib
@@ -38,3 +40,5 @@ private:
     Factory<T> mFactory;
     Method mMethod;
 };
+
+#endif