diff --git a/common/const.h b/common/const.h
index fe4469fa..bffcebc7 100644
--- a/common/const.h
+++ b/common/const.h
@@ -14,6 +14,9 @@
 ****/
 #ifndef CONST_H
 #define CONST_H
+
+#include <stddef.h> // ptrdiff_t
+
 //
 // Constants shared by the engine and dlls
 // This header file included by engine files and DLL files.
@@ -721,7 +724,7 @@ enum
 };
 
 typedef int		func_t;
-typedef int		string_t;
+typedef ptrdiff_t	string_t;
 
 typedef unsigned short	word;
 
diff --git a/engine/eiface.h b/engine/eiface.h
index e18cdedb..3bda3265 100644
--- a/engine/eiface.h
+++ b/engine/eiface.h
@@ -125,7 +125,7 @@ typedef struct enginefuncs_s
 	void	(*pfnAngleVectors)( const float *rgflVector, float *forward, float *right, float *up );
 	edict_t*	(*pfnCreateEntity)( void );
 	void	(*pfnRemoveEntity)( edict_t* e );
-	edict_t*	(*pfnCreateNamedEntity)( int className );
+	edict_t*	(*pfnCreateNamedEntity)( string_t className );
 	void	(*pfnMakeStatic)( edict_t *ent );
 	int	(*pfnEntIsOnFloor)( edict_t *e );
 	int	(*pfnDropToFloor)( edict_t* e );
@@ -168,8 +168,8 @@ typedef struct enginefuncs_s
 	void*	(*pfnPvAllocEntPrivateData)( edict_t *pEdict, long cb );
 	void*	(*pfnPvEntPrivateData)( edict_t *pEdict );
 	void	(*pfnFreeEntPrivateData)( edict_t *pEdict );
-	const char *(*pfnSzFromIndex)( int iString );
-	int	(*pfnAllocString)( const char *szValue );
+	const char *(*pfnSzFromIndex)( string_t iString );
+	string_t	(*pfnAllocString)( const char *szValue );
 	struct entvars_s *(*pfnGetVarsOfEnt)( edict_t *pEdict );
 	edict_t*	(*pfnPEntityOfEntOffset)( int iEntOffset );
 	int	(*pfnEntOffsetOfPEntity)( const edict_t *pEdict );
diff --git a/engine/progdefs.h b/engine/progdefs.h
index 2a0e133b..fb636827 100644
--- a/engine/progdefs.h
+++ b/engine/progdefs.h
@@ -85,8 +85,8 @@ typedef struct entvars_s
 	int		modelindex;
 
 	string_t		model;
-	int		viewmodel;	// player's viewmodel
-	int		weaponmodel;	// what other players see
+	string_t		viewmodel;	// player's viewmodel
+	string_t		weaponmodel;	// what other players see
 
 	vec3_t		absmin;		// BB max translated to world coord
 	vec3_t		absmax;		// BB max translated to world coord
@@ -144,7 +144,7 @@ typedef struct entvars_s
 	int		flags;
 
 	int		colormap;		// lowbyte topcolor, highbyte bottomcolor
-	int		team;
+	string_t		team;
 
 	float		max_health;
 	float		teleport_time;