diff --git a/cl_dll/ammohistory.h b/cl_dll/ammohistory.h
index f1063ae1..032d3ee3 100644
--- a/cl_dll/ammohistory.h
+++ b/cl_dll/ammohistory.h
@@ -15,6 +15,8 @@
 //
 // ammohistory.h
 //
+#ifndef AMMOHISTORY_H
+#define AMMOHISTORY_H
 
 // this is the max number of items in each bucket
 #define MAX_WEAPON_POSITIONS		MAX_WEAPON_SLOTS
@@ -137,3 +139,4 @@ public:
 };
 
 extern HistoryResource gHR;
+#endif // AMMOHISTORY_H
diff --git a/cl_dll/health.h b/cl_dll/health.h
index 132b9cb4..1007c17c 100644
--- a/cl_dll/health.h
+++ b/cl_dll/health.h
@@ -12,6 +12,8 @@
 *   without written permission from Valve LLC.
 *
 ****/
+#ifndef HEALTH_H
+#define HEALTH_H
 
 #define DMG_IMAGE_LIFE		2	// seconds that image is up
 
@@ -122,3 +124,4 @@ private:
 	void CalcDamageDirection( vec3_t vecFrom );
 	void UpdateTiles( float fTime, long bits );
 };
+#endif // HEALTH_H
diff --git a/cl_dll/hud_spectator.h b/cl_dll/hud_spectator.h
index 58026668..9cfc5519 100644
--- a/cl_dll/hud_spectator.h
+++ b/cl_dll/hud_spectator.h
@@ -5,8 +5,8 @@
 // $NoKeywords: $
 //=============================================================================
 
-#ifndef SPECTATOR_H
-#define SPECTATOR_H
+#ifndef HUD_SPECTATOR_H
+#define HUD_SPECTATOR_H
 #pragma once
 
 #include "cl_entity.h"
diff --git a/cl_dll/parsemsg.h b/cl_dll/parsemsg.h
index 0e6bd2a3..6d552413 100644
--- a/cl_dll/parsemsg.h
+++ b/cl_dll/parsemsg.h
@@ -15,6 +15,8 @@
 //
 //  parsemsg.h
 //
+#ifndef PARSEMSG_H
+#define PARSEMSG_H
 
 #define ASSERT( x )
 
@@ -30,6 +32,7 @@ float READ_COORD( void );
 float READ_ANGLE( void );
 float READ_HIRESANGLE( void );
 
+#endif // PARSEMSG_H
 
 
 
diff --git a/dlls/gamerules.h b/dlls/gamerules.h
index 6ad470d0..71036151 100644
--- a/dlls/gamerules.h
+++ b/dlls/gamerules.h
@@ -15,7 +15,8 @@
 //=========================================================
 // GameRules
 //=========================================================
-
+#ifndef GAMERULES_H
+#define GAMERULES_H
 //#include "weapons.h"
 //#include "items.h"
 class CBasePlayerItem;
@@ -361,3 +362,4 @@ protected:
 };
 
 extern DLL_GLOBAL CGameRules *g_pGameRules;
+#endif // GAMERULES_H
diff --git a/dlls/plane.h b/dlls/plane.h
index 35a17611..912062f6 100644
--- a/dlls/plane.h
+++ b/dlls/plane.h
@@ -12,12 +12,12 @@
 *   without written permission from Valve LLC.
 *
 ****/
-#ifndef PLANE_H
-#define PLANE_H
-
 //=========================================================
 // Plane
 //=========================================================
+#ifndef PLANE_H
+#define PLANE_H
+
 class CPlane
 {
 public:
diff --git a/dlls/skill.h b/dlls/skill.h
index 12b784e3..aa338362 100644
--- a/dlls/skill.h
+++ b/dlls/skill.h
@@ -15,6 +15,8 @@
 //=========================================================
 // skill.h - skill level concerns
 //=========================================================
+#ifndef SKILL_H
+#define SKILL_H
 
 struct skilldata_t
 {
@@ -143,3 +145,4 @@ extern DLL_GLOBAL int		g_iSkillLevel;
 #define SKILL_EASY		1
 #define SKILL_MEDIUM	2
 #define SKILL_HARD		3
+#endif // SKILL_H
diff --git a/dlls/spectator.h b/dlls/spectator.h
index 90f8678f..00567fc6 100644
--- a/dlls/spectator.h
+++ b/dlls/spectator.h
@@ -13,6 +13,8 @@
 *
 ****/
 // Spectator.h
+#ifndef SPECTATOR_H
+#define SPECTATOR_H
 
 class CBaseSpectator : public CBaseEntity 
 {
@@ -25,3 +27,4 @@ public:
 private:
 	void SpectatorImpulseCommand( void );
 };
+#endif // SPECTATOR_H
diff --git a/dlls/squad.h b/dlls/squad.h
index bb2784bb..c29a7199 100644
--- a/dlls/squad.h
+++ b/dlls/squad.h
@@ -4,10 +4,11 @@
 //
 // $NoKeywords: $
 //=============================================================================
-
 //=========================================================
 // squad.h
 //=========================================================
+#ifndef SQUAD_H
+#define SQUAD_H
 
 // these are special group roles that are assigned to members when the group is formed.
 // the reason these are explicitly assigned and tasks like throwing grenades to flush out 
@@ -19,3 +20,4 @@
 #define		bits_SQUAD_FLANK_RIGHT		( 1 << 1 )
 #define		bits_SQUAD_ADVANCE		( 1 << 2 )
 #define		bits_SQUAD_FLUSH_ATTACK		( 1 << 3 )
+#endif // SQUAD_H
diff --git a/dlls/squadmonster.h b/dlls/squadmonster.h
index 707910c2..132d4177 100644
--- a/dlls/squadmonster.h
+++ b/dlls/squadmonster.h
@@ -16,6 +16,8 @@
 // CSquadMonster - all the extra data for monsters that
 // form squads.
 //=========================================================
+#ifndef SQUADMONSTER_H
+#define SQUADMONSTER_H
 
 #define	SF_SQUADMONSTER_LEADER	32
 
@@ -116,3 +118,4 @@ public:
 	MONSTERSTATE GetIdealState( void );
 	Schedule_t *GetScheduleOfType( int iType );
 };
+#endif // SQUADMONSTER_H
diff --git a/dlls/util.h b/dlls/util.h
index ee7d116b..8f56cd76 100644
--- a/dlls/util.h
+++ b/dlls/util.h
@@ -12,6 +12,8 @@
 *   without written permission from Valve LLC.
 *
 ****/
+#ifndef UTIL_H
+#define UTIL_H
 //
 // Misc utility code
 //
@@ -575,3 +577,4 @@ int UTIL_SharedRandomLong( unsigned int seed, int low, int high );
 float UTIL_SharedRandomFloat( unsigned int seed, float low, float high );
 
 float UTIL_WeaponTimeBase( void );
+#endif // UTIL_H