diff --git a/src/c_cvars.cpp b/src/c_cvars.cpp
index a62f2fa952..17c3921457 100644
--- a/src/c_cvars.cpp
+++ b/src/c_cvars.cpp
@@ -293,9 +293,6 @@ bool FBaseCVar::ToBool (UCVarValue value, ECVarType type)
 		else
 			return !!strtoll (value.String, NULL, 0);
 
-	case CVAR_GUID:
-		return false;
-
 	default:
 		return false;
 	}
@@ -327,7 +324,6 @@ int FBaseCVar::ToInt (UCVarValue value, ECVarType type)
 				res = (int)strtoll (value.String, NULL, 0); 
 			break;
 		}
-	case CVAR_GUID:			res = 0; break;
 	default:				res = 0; break;
 	}
 	return res;
@@ -349,9 +345,6 @@ float FBaseCVar::ToFloat (UCVarValue value, ECVarType type)
 	case CVAR_String:
 		return (float)strtod (value.String, NULL);
 
-	case CVAR_GUID:
-		return 0.f;
-
 	default:
 		return 0.f;
 	}
@@ -382,10 +375,6 @@ const char *FBaseCVar::ToString (UCVarValue value, ECVarType type)
 		IGNORE_FORMAT_POST
 		break;
 
-	case CVAR_GUID:
-		FormatGUID (cstrbuf, countof(cstrbuf), *value.pGUID);
-		break;
-
 	default:
 		strcpy (cstrbuf, "<huh?>");
 		break;
@@ -393,24 +382,6 @@ const char *FBaseCVar::ToString (UCVarValue value, ECVarType type)
 	return cstrbuf;
 }
 
-const GUID *FBaseCVar::ToGUID (UCVarValue value, ECVarType type)
-{
-	UCVarValue trans;
-
-	switch (type)
-	{
-	case CVAR_String:
-		trans = FromString (value.String, CVAR_GUID);
-		return trans.pGUID;
-
-	case CVAR_GUID:
-		return value.pGUID;
-
-	default:
-		return NULL;
-	}
-}
-
 UCVarValue FBaseCVar::FromBool (bool value, ECVarType type)
 {
 	UCVarValue ret;
@@ -433,10 +404,6 @@ UCVarValue FBaseCVar::FromBool (bool value, ECVarType type)
 		ret.String = value ? truestr : falsestr;
 		break;
 
-	case CVAR_GUID:
-		ret.pGUID = NULL;
-		break;
-
 	default:
 		break;
 	}
@@ -467,10 +434,6 @@ UCVarValue FBaseCVar::FromInt (int value, ECVarType type)
 		ret.String = cstrbuf;
 		break;
 
-	case CVAR_GUID:
-		ret.pGUID = NULL;
-		break;
-
 	default:
 		break;
 	}
@@ -503,10 +466,6 @@ UCVarValue FBaseCVar::FromFloat (float value, ECVarType type)
 		ret.String = cstrbuf;
 		break;
 
-	case CVAR_GUID:
-		ret.pGUID = NULL;
-		break;
-
 	default:
 		break;
 	}
@@ -569,57 +528,6 @@ UCVarValue FBaseCVar::FromString (const char *value, ECVarType type)
 		ret.String = const_cast<char *>(value);
 		break;
 
-	case CVAR_GUID:
-		// {xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}
-		// 01234567890123456789012345678901234567
-		// 0         1         2         3
-
-		ret.pGUID = NULL;
-		if (value == NULL)
-		{
-			break;
-		}
-		for (i = 0; value[i] != 0 && i < 38; i++)
-		{
-			switch (i)
-			{
-			case 0:
-				if (value[i] != '{')
-					break;
-			case 9:
-			case 14:
-			case 19:
-			case 24:
-				if (value[i] != '-')
-					break;
-			case 37:
-				if (value[i] != '}')
-					break;
-			default:
-				if (value[i] < '0' || 
-					(value[i] > '9' && value[i] < 'A') || 
-					(value[i] > 'F' && value[i] < 'a') || 
-					value[i] > 'f')
-					break;
-			}
-		}
-		if (i == 38 && value[i] == 0)
-		{
-			cGUID.Data1 = strtoul (value + 1, NULL, 16);
-			cGUID.Data2 = (uint16_t)strtoul (value + 10, NULL, 16);
-			cGUID.Data3 = (uint16_t)strtoul (value + 15, NULL, 16);
-			cGUID.Data4[0] = HexToByte (value + 20);
-			cGUID.Data4[1] = HexToByte (value + 22);
-			cGUID.Data4[2] = HexToByte (value + 25);
-			cGUID.Data4[3] = HexToByte (value + 27);
-			cGUID.Data4[4] = HexToByte (value + 29);
-			cGUID.Data4[5] = HexToByte (value + 31);
-			cGUID.Data4[6] = HexToByte (value + 33);
-			cGUID.Data4[7] = HexToByte (value + 35);
-			ret.pGUID = &cGUID;
-		}
-		break;
-
 	default:
 		break;
 	}
@@ -627,39 +535,6 @@ UCVarValue FBaseCVar::FromString (const char *value, ECVarType type)
 	return ret;
 }
 
-UCVarValue FBaseCVar::FromGUID (const GUID &guid, ECVarType type)
-{
-	UCVarValue ret;
-
-	switch (type)
-	{
-	case CVAR_Bool:
-		ret.Bool = false;
-		break;
-
-	case CVAR_Int:
-		ret.Int = 0;
-		break;
-
-	case CVAR_Float:
-		ret.Float = 0.f;
-		break;
-
-	case CVAR_String:
-		ret.pGUID = &guid;
-		ret.String = ToString (ret, CVAR_GUID);
-		break;
-
-	case CVAR_GUID:
-		ret.pGUID = &guid;
-		break;
-
-	default:
-		break;
-	}
-
-	return ret;
-}
 FBaseCVar *cvar_set (const char *var_name, const char *val)
 {
 	FBaseCVar *var;
@@ -1053,80 +928,6 @@ int FColorCVar::ToInt2 (UCVarValue value, ECVarType type)
 	return ret;
 }
 
-//
-// GUID cvar implementation
-//
-
-FGUIDCVar::FGUIDCVar (const char *name, const GUID *def, uint32_t flags, void (*callback)(FGUIDCVar &))
-: FBaseCVar (name, flags, reinterpret_cast<void (*)(FBaseCVar &)>(callback))
-{
-	if (def != NULL)
-	{
-		DefaultValue = *def;
-		if (Flags & CVAR_ISDEFAULT)
-			Value = *def;
-	}
-	else
-	{
-		memset (&Value, 0, sizeof(DefaultValue));
-		memset (&DefaultValue, 0, sizeof(DefaultValue));
-	}
-}
-
-ECVarType FGUIDCVar::GetRealType () const
-{
-	return CVAR_GUID;
-}
-
-UCVarValue FGUIDCVar::GetGenericRep (ECVarType type) const
-{
-	return FromGUID (Value, type);
-}
-
-UCVarValue FGUIDCVar::GetFavoriteRep (ECVarType *type) const
-{
-	UCVarValue ret;
-	*type = CVAR_GUID;
-	ret.pGUID = &Value;
-	return ret;
-}
-
-UCVarValue FGUIDCVar::GetGenericRepDefault (ECVarType type) const
-{
-	return FromGUID (DefaultValue, type);
-}
-
-UCVarValue FGUIDCVar::GetFavoriteRepDefault (ECVarType *type) const
-{
-	UCVarValue ret;
-	*type = CVAR_GUID;
-	ret.pGUID = &DefaultValue;
-	return ret;
-}
-
-void FGUIDCVar::SetGenericRepDefault (UCVarValue value, ECVarType type)
-{
-	const GUID *guid = ToGUID (value, type);
-	if (guid != NULL)
-	{
-		Value = *guid;
-		if (Flags & CVAR_ISDEFAULT)
-		{
-			SetGenericRep (value, type);
-			Flags |= CVAR_ISDEFAULT;
-		}
-	}
-}
-
-void FGUIDCVar::DoSet (UCVarValue value, ECVarType type)
-{
-	const GUID *guid = ToGUID (value, type);
-	if (guid != NULL)
-	{
-		Value = *guid;
-	}
-}
-
 //
 // More base cvar stuff
 //
diff --git a/src/c_cvars.h b/src/c_cvars.h
index 11166098b8..875946995f 100644
--- a/src/c_cvars.h
+++ b/src/c_cvars.h
@@ -34,7 +34,7 @@
 #ifndef __C_CVARS_H__
 #define __C_CVARS_H__
 
-#include "doomtype.h"
+#include "zstring.h"
 #include "tarray.h"
 
 /*
@@ -73,7 +73,6 @@ union UCVarValue
 	int Int;
 	float Float;
 	const char *String;
-	const GUID *pGUID;
 };
 
 enum ECVarType
@@ -85,8 +84,7 @@ enum ECVarType
 	CVAR_Color,		// stored as CVAR_Int
 	CVAR_DummyBool,		// just redirects to another cvar
 	CVAR_DummyInt,		// just redirects to another cvar
-	CVAR_Dummy,			// Unknown
-	CVAR_GUID
+	CVAR_Dummy			// Unknown
 };
 
 class FConfigFile;
@@ -140,12 +138,10 @@ protected:
 	static int ToInt (UCVarValue value, ECVarType type);
 	static float ToFloat (UCVarValue value, ECVarType type);
 	static const char *ToString (UCVarValue value, ECVarType type);
-	static const GUID *ToGUID (UCVarValue value, ECVarType type);
 	static UCVarValue FromBool (bool value, ECVarType type);
 	static UCVarValue FromInt (int value, ECVarType type);
 	static UCVarValue FromFloat (float value, ECVarType type);
 	static UCVarValue FromString (const char *value, ECVarType type);
-	static UCVarValue FromGUID (const GUID &value, ECVarType type);
 
 	char *Name;
 	FString SafeValue;
@@ -403,31 +399,6 @@ protected:
 	int BitNum;
 };
 
-class FGUIDCVar : public FBaseCVar
-{
-public:
-	FGUIDCVar (const char *name, const GUID *defguid, uint32_t flags, void (*callback)(FGUIDCVar &)=NULL);
-
-	virtual ECVarType GetRealType () const;
-
-	virtual UCVarValue GetGenericRep (ECVarType type) const;
-	virtual UCVarValue GetFavoriteRep (ECVarType *type) const;
-	virtual UCVarValue GetGenericRepDefault (ECVarType type) const;
-	virtual UCVarValue GetFavoriteRepDefault (ECVarType *type) const;
-	virtual void SetGenericRepDefault (UCVarValue value, ECVarType type);
-
-	const GUID &operator= (const GUID &guidval)
-		{ UCVarValue val; val.pGUID = &guidval; SetGenericRep (val, CVAR_GUID); return guidval; }
-	inline operator const GUID & () const { return Value; }
-	inline const GUID &operator *() const { return Value; }
-
-protected:
-	virtual void DoSet (UCVarValue value, ECVarType type);
-
-	GUID Value;
-	GUID DefaultValue;
-};
-
 extern int cvar_defflags;
 
 FBaseCVar *cvar_set (const char *var_name, const char *value);
diff --git a/src/posix/cocoa/st_start.mm b/src/posix/cocoa/st_start.mm
index d10722ffb2..508cdf0bfe 100644
--- a/src/posix/cocoa/st_start.mm
+++ b/src/posix/cocoa/st_start.mm
@@ -36,6 +36,7 @@
 #import <Foundation/NSRunLoop.h>
 
 #include "c_cvars.h"
+#include "doomtype.h"
 #include "st_console.h"
 #include "st_start.h"
 
diff --git a/src/r_data/colormaps.h b/src/r_data/colormaps.h
index 128a6eeb73..cb57f8b796 100644
--- a/src/r_data/colormaps.h
+++ b/src/r_data/colormaps.h
@@ -1,6 +1,8 @@
 #ifndef __RES_CMAP_H
 #define __RES_CMAP_H
 
+#include "doomtype.h"
+
 struct lightlist_t;
 
 void R_InitColormaps ();
diff --git a/src/rendering/gl/textures/gl_hwtexture.cpp b/src/rendering/gl/textures/gl_hwtexture.cpp
index 01d818f5b8..74799fc889 100644
--- a/src/rendering/gl/textures/gl_hwtexture.cpp
+++ b/src/rendering/gl/textures/gl_hwtexture.cpp
@@ -29,6 +29,7 @@
 #include "gl_load/gl_system.h"
 #include "templates.h"
 #include "c_cvars.h"
+#include "doomtype.h"
 #include "r_data/colormaps.h"
 #include "hwrenderer/textures/hw_material.h"
 
diff --git a/src/utility/i_time.cpp b/src/utility/i_time.cpp
index 6bd18502e9..26d10e3c89 100644
--- a/src/utility/i_time.cpp
+++ b/src/utility/i_time.cpp
@@ -39,6 +39,7 @@
 #include "doomdef.h"
 #include "c_cvars.h"
 #include "doomstat.h"
+#include "doomtype.h"
 
 //==========================================================================
 //