diff --git a/src/d_event.h b/src/d_event.h
index 1079ce39..63e67adb 100644
--- a/src/d_event.h
+++ b/src/d_event.h
@@ -119,6 +119,9 @@ typedef enum
   // Savegame slot numbers occupy the second byte of buttons.    
   BTS_SAVEMASK    = (4+8+16),
   BTS_SAVESHIFT   = 2,
+
+  // [crispy] demo joined.
+  BT_JOIN = 64
   
 } buttoncode_t;
 
diff --git a/src/d_main.c b/src/d_main.c
index 00d03ac4..225a43b3 100644
--- a/src/d_main.c
+++ b/src/d_main.c
@@ -2648,7 +2648,8 @@ void D_DoomMain(void)
       if (autostart || netgame)
 	{
 	  G_InitNew(startskill, startepisode, startmap);
-	  if (demorecording)
+	  // [crispy] no need to write a demo header in demo continue mode
+	  if (demorecording && gameaction != ga_playdemo)
 	    G_BeginRecording();
 	}
       else
diff --git a/src/g_game.c b/src/g_game.c
index 3b5b7988..03a4aa6e 100644
--- a/src/g_game.c
+++ b/src/g_game.c
@@ -96,6 +96,7 @@ boolean         paused;
 boolean         sendpause;     // send a pause event next tic
 boolean         sendsave;      // send a save event next tic
 boolean         sendreload;    // send a reload level event next tic
+boolean         sendjoin;
 boolean         usergame;      // ok to save / end game
 boolean         timingdemo;    // if true, exit with report on completion
 boolean         fastdemo;      // if true, run at full speed -- killough
@@ -135,6 +136,9 @@ int             default_complevel;
 
 boolean         strictmode, default_strictmode;
 
+// [crispy] store last cmd to track joins
+static ticcmd_t* last_cmd = NULL;
+
 //
 // controls (have defaults)
 //
@@ -617,6 +621,12 @@ void G_BuildTiccmd(ticcmd_t* cmd)
     cmd->buttons = BT_SPECIAL | (BTS_RELOAD & BT_SPECIALMASK);
   }
 
+  if (sendjoin)
+  {
+    sendjoin = false;
+    cmd->buttons |= BT_JOIN;
+  }
+
   // low-res turning
 
   if (lowres_turn)
@@ -860,6 +870,12 @@ boolean G_Responder(event_t* ev)
 	  return true;
 	}
 
+      if (M_InputActivated(input_demo_join))
+      {
+        sendjoin = true;
+        return true;
+      }
+
       // killough 10/98:
       // Don't pop up menu, if paused in middle
       // of demo playback, or if automap active.
@@ -967,12 +983,41 @@ boolean G_Responder(event_t* ev)
 // [crispy] demo progress bar
 int defdemotics = 0, deftotaldemotics;
 
+static char *defdemoname;
+
 #define DEMOMARKER    0x80
 
+// Stay in the game, hand over controls to the player and continue recording the
+// demo under a different name
+static void G_JoinDemo(void)
+{
+  byte *actualbuffer = demobuffer;
+  int actualsize = maxdemosize;
+
+  // [crispy] find a new name for the continued demo
+  G_RecordDemo(defdemoname);
+
+  // [crispy] discard the newly allocated demo buffer
+  Z_Free(demobuffer);
+  demobuffer = actualbuffer;
+  maxdemosize = actualsize;
+
+  // [crispy] continue recording
+  demoplayback = false;
+
+  // clear progress demo bar
+  ST_Start();
+
+  doomprintf("Demo recording: %s", demoname);
+}
+
 static void G_ReadDemoTiccmd(ticcmd_t *cmd)
 {
   if (*demo_p == DEMOMARKER)
+  {
+    last_cmd = cmd; // [crispy] remember last cmd to track joins
     G_CheckDemoStatus();      // end of demo data stream
+  }
   else
     {
       cmd->forwardmove = ((signed char)*demo_p++);
@@ -1002,12 +1047,21 @@ static void G_ReadDemoTiccmd(ticcmd_t *cmd)
     }
 }
 
+static void CheckDemoBuffer(size_t size)
+{
+  ptrdiff_t position = demo_p - demobuffer;
+  if (position + size > maxdemosize)
+  {
+    maxdemosize += size + 128 * 1024; // add another 128K
+    demobuffer = Z_Realloc(demobuffer, maxdemosize, PU_STATIC, 0);
+    demo_p = position + demobuffer;
+  }
+}
+
 // Demo limits removed -- killough
 
 static void G_WriteDemoTiccmd(ticcmd_t* cmd)
 {
-  ptrdiff_t position = demo_p - demobuffer;
-
   if (M_InputGameActive(input_demo_quit)) // press to end demo recording
     G_CheckDemoStatus();
 
@@ -1025,14 +1079,7 @@ static void G_WriteDemoTiccmd(ticcmd_t* cmd)
     demo_p[4] = cmd->buttons;
   }
 
-  if (position+16 > maxdemosize)   // killough 8/23/98
-    {
-      // no more space
-      maxdemosize += 128*1024;   // add another 128K  -- killough
-      demobuffer = Z_Realloc(demobuffer,maxdemosize, PU_STATIC, 0);
-      demo_p = position + demobuffer;  // back on track
-      // end of main demo limit changes -- killough
-    }
+  CheckDemoBuffer(16);   // killough 8/23/98
 
   G_ReadDemoTiccmd (cmd);         // make SURE it is exactly the same
 }
@@ -1351,8 +1398,6 @@ static void G_DoWorldDone(void)
 
 #define MIN_MAXPLAYERS 32
 
-static char *defdemoname;
-
 #define INVALID_DEMO(a, b) \
    do \
    { \
@@ -1375,6 +1420,13 @@ static void G_DoPlayDemo(void)
   if (gameaction != ga_loadgame)      // killough 12/98: support -loadgame
     basetic = gametic;  // killough 9/29/98
 
+  // [crispy] in demo continue mode free the obsolete demo buffer
+  // of size 'maxdemosize' previously allocated in G_RecordDemo()
+  if (demorecording)
+  {
+      Z_Free(demobuffer);
+  }
+
   ExtractFileBase(defdemoname,basename);           // killough
 
   lumpnum = W_GetNumForName(basename);
@@ -1583,6 +1635,8 @@ static void G_DoPlayDemo(void)
 
   gameaction = ga_nothing;
 
+  maxdemosize = lumplength;
+
   // [crispy] demo progress bar
   {
     byte *demo_ptr = demo_p;
@@ -2120,10 +2174,16 @@ void G_Ticker(void)
 
 	      memcpy(cmd, &netcmds[i], sizeof *cmd);
 
+	      // catch BT_JOIN before G_ReadDemoTiccmd overwrites it
+	      if (demoplayback && cmd->buttons & BT_JOIN)
+		G_JoinDemo();
+
 	      if (demoplayback)
 		G_ReadDemoTiccmd(cmd);
 
-	      if (demorecording)
+	      // [crispy] do not record tics while still playing back in demo
+	      // continue mode
+	      if (demorecording && !demoplayback)
 		G_WriteDemoTiccmd(cmd);
 
 	      // check for turbo cheats
@@ -3130,7 +3190,11 @@ void G_RecordDemo(char *name)
 
   for(; j <= 99999 && !M_access(demoname, F_OK); ++j)
   {
-    M_snprintf(demoname, demoname_size, "%s-%05d.lmp", name, j);
+    char *str = M_StringDuplicate(name);
+    if (M_StringCaseEndsWith(str, ".lmp"))
+      str[strlen(str) - 4] = '\0';
+    M_snprintf(demoname, demoname_size, "%s-%05d.lmp", str, j);
+    free(str);
   }
 
   //!
@@ -3569,7 +3633,6 @@ extern char **dehfiles;
 
 static void G_AddDemoFooter(void)
 {
-  ptrdiff_t position = demo_p - demobuffer;
   char *tmp = NULL;
   size_t len = 0;
   int i;
@@ -3636,12 +3699,7 @@ static void G_AddDemoFooter(void)
 
   mem_get_buf(stream, (void **)&tmp, &len);
 
-  if (position + len > maxdemosize)
-  {
-    maxdemosize += len;
-    demobuffer = Z_Realloc(demobuffer, maxdemosize, PU_STATIC, 0);
-    demo_p = position + demobuffer;
-  }
+  CheckDemoBuffer(len);
 
   memcpy(demo_p, tmp, len);
   demo_p += len;
@@ -3659,6 +3717,44 @@ static void G_AddDemoFooter(void)
 
 boolean G_CheckDemoStatus(void)
 {
+  // [crispy] catch the last cmd to track joins
+  ticcmd_t* cmd = last_cmd;
+  last_cmd = NULL;
+
+  if (demoplayback)
+    {
+      if (demorecording)
+      {
+        demoplayback = false;
+
+        // clear progress demo bar
+        ST_Start();
+
+        // [crispy] record demo join
+        if (cmd != NULL)
+        {
+          cmd->buttons |= BT_JOIN;
+        }
+
+        return true;
+      }
+
+      if (singledemo)
+        I_SafeExit(0);  // killough
+
+      // [FG] ignore empty demo lumps
+      if (demobuffer)
+      {
+        Z_ChangeTag(demobuffer, PU_CACHE);
+      }
+
+      G_ReloadDefaults();    // killough 3/1/98
+      netgame = false;       // killough 3/29/98
+      deathmatch = false;
+      D_AdvanceDemo();
+      return true;
+    }
+
   if (demorecording)
     {
       demorecording = false;
@@ -3691,22 +3787,6 @@ boolean G_CheckDemoStatus(void)
                (unsigned) gametic * (double) TICRATE / realtics);
     }
 
-  if (demoplayback)
-    {
-      if (singledemo)
-        I_SafeExit(0);  // killough
-
-      // [FG] ignore empty demo lumps
-      if (demobuffer)
-      {
-      Z_ChangeTag(demobuffer, PU_CACHE);
-      }
-      G_ReloadDefaults();    // killough 3/1/98
-      netgame = false;       // killough 3/29/98
-      deathmatch = false;
-      D_AdvanceDemo();
-      return true;
-    }
   return false;
 }
 
diff --git a/src/m_input.h b/src/m_input.h
index 700ce0bd..d48583b9 100644
--- a/src/m_input.h
+++ b/src/m_input.h
@@ -91,6 +91,7 @@ enum
   input_spy,
   input_demo_quit,
   input_demo_fforward,
+  input_demo_join,
   input_speed_up,
   input_speed_down,
   input_speed_default,
diff --git a/src/m_menu.c b/src/m_menu.c
index ef3c81f9..bfd87577 100644
--- a/src/m_menu.c
+++ b/src/m_menu.c
@@ -2893,11 +2893,12 @@ setup_menu_t keys_settings4[] =  // Key Binding screen strings
   {"DEMOS" ,S_SKIP|S_TITLE,m_null,KB_X,M_Y+5*M_SPC},
   {"FAST-FORWARD" ,S_INPUT,m_scrn,KB_X,M_Y+6*M_SPC,{0},input_demo_fforward},
   {"FINISH DEMO"  ,S_INPUT,m_scrn,KB_X,M_Y+7*M_SPC,{0},input_demo_quit},
+  {"JOIN DEMO"    ,S_INPUT,m_scrn,KB_X,M_Y+8*M_SPC,{0},input_demo_join},
 
   // [FG] reload current level / go to next level
-  {"MISCELLANEOUS",S_SKIP|S_TITLE,m_null,KB_X,M_Y+9*M_SPC},
-  {"RELOAD LEVEL" ,S_INPUT,m_scrn,KB_X,M_Y+10*M_SPC,{0},input_menu_reloadlevel},
-  {"NEXT LEVEL"   ,S_INPUT,m_scrn,KB_X,M_Y+11*M_SPC,{0},input_menu_nextlevel},
+  {"MISCELLANEOUS",S_SKIP|S_TITLE,m_null,KB_X,M_Y+10*M_SPC},
+  {"RELOAD LEVEL" ,S_INPUT,m_scrn,KB_X,M_Y+11*M_SPC,{0},input_menu_reloadlevel},
+  {"NEXT LEVEL"   ,S_INPUT,m_scrn,KB_X,M_Y+12*M_SPC,{0},input_menu_nextlevel},
 
   {"<- PREV", S_SKIP|S_PREV,m_null,M_X_PREV,M_Y_PREVNEXT, {keys_settings3}},
   {"NEXT ->", S_SKIP|S_NEXT,m_null,M_X_NEXT,M_Y_PREVNEXT, {keys_settings5}},
diff --git a/src/m_misc.c b/src/m_misc.c
index 07fec8cc..59745954 100644
--- a/src/m_misc.c
+++ b/src/m_misc.c
@@ -903,6 +903,14 @@ default_t defaults[] = {
     input_demo_quit, { {0, 0} }
   },
 
+  {
+    "input_demo_join",
+    NULL, NULL,
+    {0}, {UL,UL}, input, ss_keys, wad_no,
+    "key to continue recording current demo",
+    input_demo_join, { {0, 0} }
+  },
+
   {
     "input_demo_fforward",
     NULL, NULL,