diff --git a/src/d_clisrv.c b/src/d_clisrv.c
index 939d53de..76b5c95d 100644
--- a/src/d_clisrv.c
+++ b/src/d_clisrv.c
@@ -1733,9 +1733,7 @@ static boolean CL_ServerConnectionSearchTicker(boolean viams, tic_t *asksent)
 {
 #ifndef NONET
 	INT32 i;
-#endif
 
-#ifndef NONET
 	// serverlist is updated by GetPacket function
 	if (serverlistcount > 0)
 	{
@@ -1769,7 +1767,20 @@ static boolean CL_ServerConnectionSearchTicker(boolean viams, tic_t *asksent)
 				serverlist[i].info.fileneeded);
 			CONS_Printf(M_GetText("Checking files...\n"));
 			i = CL_CheckFiles();
-			if (i == 2) // cannot join for some reason
+			if (i == 3) // too many files
+			{
+				D_QuitNetGame();
+				CL_Reset();
+				D_StartTitle();
+				M_StartMessage(M_GetText(
+					"You have too many WAD files loaded\n"
+					"to add ones the server is using.\n"
+					"Please restart SRB2 before connecting.\n\n"
+					"Press ESC\n"
+				), NULL, MM_NOTHING);
+				return false;
+			}
+			else if (i == 2) // cannot join for some reason
 			{
 				D_QuitNetGame();
 				CL_Reset();
diff --git a/src/d_netcmd.c b/src/d_netcmd.c
index f4916756..d7bbb0aa 100644
--- a/src/d_netcmd.c
+++ b/src/d_netcmd.c
@@ -3080,6 +3080,11 @@ static void Got_RequestAddfilecmd(UINT8 **cp, INT32 playernum)
 	boolean kick = false;
 	boolean toomany = false;
 	INT32 i;
+	size_t packetsize = 0;
+	serverinfo_pak *dummycheck = NULL;
+
+	// Shut the compiler up.
+	(void)dummycheck;
 
 	READSTRINGN(*cp, filename, 240);
 	READMEM(*cp, md5sum, 16);
@@ -3105,7 +3110,14 @@ static void Got_RequestAddfilecmd(UINT8 **cp, INT32 playernum)
 		return;
 	}
 
-	if (numwadfiles >= MAX_WADFILES) // a more comprehensive check in internal; bare minimum of out-of-bounds for public next
+	// See W_LoadWadFile in w_wad.c
+	for (i = 0; i < numwadfiles; i++)
+		packetsize += nameonlylength(wadfiles[i]->filename) + 22;
+
+	packetsize += nameonlylength(filename) + 22;
+
+	if ((numwadfiles >= MAX_WADFILES)
+	|| (packetsize > sizeof(dummycheck->fileneeded)))
 		toomany = true;
 	else
 		ncs = findfile(filename,md5sum,true);
diff --git a/src/d_netfil.c b/src/d_netfil.c
index bf4e5987..479fd60d 100644
--- a/src/d_netfil.c
+++ b/src/d_netfil.c
@@ -330,6 +330,11 @@ INT32 CL_CheckFiles(void)
 	INT32 i, j;
 	char wadfilename[MAX_WADPATH];
 	INT32 ret = 1;
+	size_t packetsize = 0;
+	serverinfo_pak *dummycheck = NULL;
+
+	// Shut the compiler up.
+	(void)dummycheck;
 
 //	if (M_CheckParm("-nofiles"))
 //		return 1;
@@ -378,6 +383,10 @@ INT32 CL_CheckFiles(void)
 		return 1;
 	}
 
+	// See W_LoadWadFile in w_wad.c
+	for (i = 0; i < numwadfiles; i++)
+		packetsize += nameonlylength(wadfiles[i]->filename) + 22;
+
 	for (i = 1; i < fileneedednum; i++)
 	{
 		CONS_Debug(DBG_NETPLAY, "searching for '%s' ", fileneeded[i].filename);
@@ -397,6 +406,12 @@ INT32 CL_CheckFiles(void)
 		if (fileneeded[i].status != FS_NOTFOUND || !fileneeded[i].important)
 			continue;
 
+		packetsize += nameonlylength(fileneeded[i].filename) + 22;
+
+		if ((numwadfiles >= MAX_WADFILES)
+		|| (packetsize > sizeof(dummycheck->fileneeded)))
+			return 3;
+
 		fileneeded[i].status = findfile(fileneeded[i].filename, fileneeded[i].md5sum, true);
 		CONS_Debug(DBG_NETPLAY, "found %d\n", fileneeded[i].status);
 		if (fileneeded[i].status != FS_FOUND)