diff --git a/src/doomdef.h b/src/doomdef.h
index a4a8ff224..793537f82 100644
--- a/src/doomdef.h
+++ b/src/doomdef.h
@@ -157,6 +157,9 @@ extern FILE *logstream;
 // Otherwise we can't force updates!
 #endif
 
+// Maintain compatibility with 1.0.x record attack replays?
+#define DEMO_COMPAT_100
+
 // Does this version require an added patch file?
 // Comment or uncomment this as necessary.
 //#define USE_PATCH_DTA
diff --git a/src/g_game.c b/src/g_game.c
index 5ea653e40..f4110b2a9 100644
--- a/src/g_game.c
+++ b/src/g_game.c
@@ -4756,7 +4756,7 @@ char *G_BuildMapTitle(INT32 mapnum)
 // DEMO RECORDING
 //
 
-#define DEMOVERSION 0x0001
+#define DEMOVERSION 0x0002
 #define DEMOHEADER  "\xF0" "KartReplay" "\x0F"
 
 #define DF_GHOST        0x01 // This demo contains ghost data too!
@@ -6522,6 +6522,10 @@ UINT8 G_CmpDemoTime(char *oldname, char *newname)
 	{
 	case DEMOVERSION: // latest always supported
 		break;
+#ifdef DEMO_COMPAT_100
+	case 0x0001:
+		I_Error("You need to implement demo compat here, doofus! %s:%s", __FILE__, __LINE__);
+#endif
 	// too old, cannot support.
 	default:
 		CONS_Alert(CONS_NOTICE, M_GetText("File '%s' invalid format. It will be overwritten.\n"), oldname);
@@ -6664,6 +6668,10 @@ void G_DoPlayDemo(char *defdemoname)
 	{
 	case DEMOVERSION: // latest always supported
 		break;
+#ifdef DEMO_COMPAT_100
+	case 0x0001:
+		I_Error("You need to implement demo compat here, doofus! %s:%s", __FILE__, __LINE__);
+#endif
 	// too old, cannot support.
 	default:
 		snprintf(msg, 1024, M_GetText("%s is an incompatible replay format and cannot be played.\n"), pdemoname);
@@ -7033,6 +7041,10 @@ void G_AddGhost(char *defdemoname)
 	{
 	case DEMOVERSION: // latest always supported
 		break;
+#ifdef DEMO_COMPAT_100
+	case 0x0001:
+		I_Error("You need to implement demo compat here, doofus! %s:%s", __FILE__, __LINE__);
+#endif
 	// too old, cannot support.
 	default:
 		CONS_Alert(CONS_NOTICE, M_GetText("Ghost %s: Demo version incompatible.\n"), pdemoname);
@@ -7233,6 +7245,10 @@ void G_UpdateStaffGhostName(lumpnum_t l)
 	{
 	case DEMOVERSION: // latest always supported
 		break;
+#ifdef DEMO_COMPAT_100
+	case 0x0001:
+		I_Error("You need to implement demo compat here, doofus! %s:%s", __FILE__, __LINE__);
+#endif
 	// too old, cannot support.
 	default:
 		goto fail;
@@ -7344,6 +7360,10 @@ void G_DoPlayMetal(void)
 	{
 	case DEMOVERSION: // latest always supported
 		break;
+#ifdef DEMO_COMPAT_100
+	case 0x0001:
+		I_Error("You need to implement demo compat here, doofus! %s:%s", __FILE__, __LINE__);
+#endif
 	// too old, cannot support.
 	default:
 		CONS_Alert(CONS_WARNING, M_GetText("Failed to load bot recording for this map, format version incompatible.\n"));