diff --git a/src/pr2_cmds.c b/src/pr2_cmds.c
index 7a705a6a..abcc029b 100644
--- a/src/pr2_cmds.c
+++ b/src/pr2_cmds.c
@@ -1572,6 +1572,10 @@ void PF2_infokey(int e1, char *key, char *valbuff, int sizebuff)
 			snprintf(ov, sizeof(ov), "%d", cl->file_percent ? cl->file_percent : -1); //bliP: file percent
 		else if (!strcmp(key, "ping"))
 			snprintf(ov, sizeof(ov), "%d", (int)SV_CalcPing(cl));
+#ifdef FTE_PEXT_CSQC
+		else if (!strcmp(key, "csqcactive") || !strcmp(key, "*csqcactive"))
+			snprintf(ov, sizeof(ov), "%d", (int)cl->csqcactive);
+#endif
 		else if (!strcmp(key, "*userid"))
 			snprintf(ov, sizeof(ov), "%d", cl->userid);
 		else if (!strncmp(key, "login", 6))
diff --git a/src/server.h b/src/server.h
index 70c8cd8f..190a201e 100644
--- a/src/server.h
+++ b/src/server.h
@@ -128,6 +128,9 @@ typedef struct
 
 	entity_state_t static_entities[512];
 	int            static_entity_count;
+#ifdef FTE_PEXT_CSQC
+	unsigned int   csqcchecksum;
+#endif
 } server_t;
 
 #define	NUM_SPAWN_PARMS 16
@@ -345,6 +348,10 @@ typedef struct client_s
 	} voice_target;
 #endif
 
+#ifdef FTE_PEXT_CSQC
+	qbool			csqcactive;
+#endif
+
 	//===== NETWORK ============
 	qbool           process_pext;             // true if we wait for reply from client on "cmd pext" command.
 	int             chokecount;
diff --git a/src/sv_init.c b/src/sv_init.c
index 806b11c6..d18f47f8 100644
--- a/src/sv_init.c
+++ b/src/sv_init.c
@@ -196,6 +196,33 @@ static unsigned SV_CheckModel(char *mdl)
 	return crc;
 }
 
+#ifdef FTE_PEXT_CSQC
+static void SV_LoadCSQC(void)
+{
+	extern cvar_t sv_csqc_progname;
+	int size;
+
+	byte *file = FS_LoadTempFile(sv_csqc_progname.string, &size);
+	if (file)
+	{
+		char text[64];
+		sv.csqcchecksum = Com_BlockChecksum(file, size);
+		sprintf(text, "0x%x", sv.csqcchecksum);
+		Info_SetValueForStarKey(svs.info, "*csprogs", text, MAX_SERVERINFO_STRING);
+		sprintf(text, "0x%x", (unsigned int)size);
+		Info_SetValueForStarKey(svs.info, "*csprogssize", text, MAX_SERVERINFO_STRING);
+		Info_SetValueForStarKey(svs.info, "*csprogsname", sv_csqc_progname.string, MAX_SERVERINFO_STRING);
+	}
+	else
+	{
+		sv.csqcchecksum = 0;
+		Info_SetValueForStarKey(svs.info, "*csprogs", "", MAX_SERVERINFO_STRING);
+		Info_SetValueForStarKey(svs.info, "*csprogssize", "", MAX_SERVERINFO_STRING);
+		Info_SetValueForStarKey(svs.info, "*csprogsname", "", MAX_SERVERINFO_STRING);
+	}
+}
+#endif
+
 /*
 ================
 SV_SpawnServer
@@ -339,6 +366,10 @@ void SV_SpawnServer(char *mapname, qbool devmap, char* entityfile, qbool loading
 
 	sv.time = 1.0;
 
+#ifdef FTE_PEXT_CSQC
+	SV_LoadCSQC();
+#endif
+
 	// load progs to get entity field count
 	// which determines how big each edict is
 	// and allocate edicts
diff --git a/src/sv_main.c b/src/sv_main.c
index 97935baf..a759112e 100644
--- a/src/sv_main.c
+++ b/src/sv_main.c
@@ -194,6 +194,10 @@ cvar_t sv_pext_mvdsv_serversideweapon = { "sv_pext_mvdsv_serversideweapon", "1"
 
 cvar_t sv_extlimits = { "sv_extlimits", "2" };
 
+#ifdef FTE_PEXT_CSQC
+cvar_t sv_csqc_progname = { "sv_csqc_progname", "csprogs.dat" };
+#endif
+
 qbool sv_error = false;
 
 client_t *WatcherId = NULL; // QW262
@@ -3529,6 +3533,10 @@ void SV_InitLocal (void)
 
 	Cvar_Register(&sv_mod_extensions);
 
+#ifdef FTE_PEXT_CSQC
+	Cvar_Register (&sv_csqc_progname);
+#endif
+
 // QW262 -->
 	Cmd_AddCommand ("svadmin", SV_Admin_f);
 // <-- QW262
@@ -3570,6 +3578,9 @@ void SV_InitLocal (void)
 #ifdef FTE_PEXT_SPAWNSTATIC2
 	svs.fteprotocolextensions |= FTE_PEXT_SPAWNSTATIC2;
 #endif
+#ifdef FTE_PEXT_CSQC
+	svs.fteprotocolextensions |= FTE_PEXT_CSQC;
+#endif
 
 #ifdef FTE_PEXT2_VOICECHAT
 	svs.fteprotocolextensions2 |= FTE_PEXT2_VOICECHAT;
diff --git a/src/sv_user.c b/src/sv_user.c
index 71f6d70d..9623aac4 100644
--- a/src/sv_user.c
+++ b/src/sv_user.c
@@ -318,6 +318,17 @@ static void Cmd_New_f (void)
 	if (!gamedir[0])
 		gamedir = "qw";
 
+#ifdef FTE_PEXT_CSQC
+	if (sv.csqcchecksum && !(sv_client->fteprotocolextensions & FTE_PEXT_CSQC))
+	{
+		SV_ClientPrintf(sv_client, PRINT_HIGH, "\n\n\n\n"
+			"This server is using CSQC - you are missing out due to your choice of outdated client / protocol!\n"
+			"Please upgrade to one of the following:\n"
+			"> ezQuake (https://www.ezquake.com) (hardcoded KTX support)\n"
+			"> FTEQW (http://fte.triptohell.info/)\n");
+	}
+#endif
+
 #ifdef FTE_PEXT_FLOATCOORDS
 	if (msg_coordsize > 2 && !(sv_client->fteprotocolextensions & FTE_PEXT_FLOATCOORDS))
 	{
@@ -1416,10 +1427,14 @@ static void Cmd_Download_f(void)
 
 	if (sv_client->special)
 		allow_dl = true; // NOTE: user used techlogin, allow dl anything in quake dir in such case!
-	else if (!strstr(name, "/"))
-		allow_dl = false; // should be in subdir
 	else if (!(int)allow_download.value)
 		allow_dl = false; // global allow check
+#ifdef FTE_PEXT_CSQC
+	else if (!strncmp(name, "csprogs.dat", 11))
+		allow_dl = true; // we always allow csprogs.dat to be downloaded (if downloads are permitted).
+#endif
+	else if (!strstr(name, "/"))
+		allow_dl = false; // should be in subdir
 	else if (!strncmp(name, "skins/", 6))
 		allow_dl = allow_download_skins.value; // skins
 	else if (!strncmp(name, "progs/", 6))
@@ -3042,6 +3057,18 @@ void SV_Voice_UnmuteAll_f(void)
 
 #endif // FTE_PEXT2_VOICECHAT
 
+#ifdef FTE_PEXT_CSQC
+void SV_EnableClientsCSQC(void)
+{
+	sv_client->csqcactive = true;
+}
+
+void SV_DisableClientsCSQC(void)
+{
+	sv_client->csqcactive = false;
+}
+#endif
+
 /*
  * Parse protocol extensions which supported by client.
  * This is workaround for the proxy case, like: qwfwd. We can't use it in case of qizmo thought.
@@ -3293,6 +3320,11 @@ static ucmd_t ucmds[] =
 	{"unmuteall", SV_Voice_UnmuteAll_f, false}, /*reenables*/
 #endif
 
+#ifdef FTE_PEXT_CSQC
+	{"enablecsqc",	SV_EnableClientsCSQC, false},
+	{"disablecsqc",	SV_DisableClientsCSQC, false},
+#endif
+
 	{"pext", Cmd_PEXT_f, false}, // user reply with supported protocol extensions.
 
 #if defined(SERVERONLY) && defined(WWW_INTEGRATION)