diff --git a/base/all-all/compdb.lmp b/base/all-all/compdb.lmp
index 5508c5855..0a984725b 100644
--- a/base/all-all/compdb.lmp
+++ b/base/all-all/compdb.lmp
@@ -19,6 +19,11 @@
           }
         ]
       },
+      {
+        "name": "doomsday_of_uac_e1m8",
+        "md5": "32fc3115a3162b623f0d0f4e7dee6861",
+        "complevel": "1.9"
+      },
       {
         "name": "hell_revealed_map19",
         "md5": "811a0c97777a198bc9b2bb558cb46e6a",
@@ -34,7 +39,6 @@
         "md5": "145c4dfcf843f2b92c73036ba0e1d98a",
         "options": [ {"name": "comp_vile", "value": 1} ]
       },
-
       {
         "name": "hell_to_pay_map14",
         "md5": "5379c080299eb961792b50ad96821543",
diff --git a/src/g_compatibility.c b/src/g_compatibility.c
index 56207e06e..977a7a557 100644
--- a/src/g_compatibility.c
+++ b/src/g_compatibility.c
@@ -20,6 +20,7 @@
 
 #include "doomstat.h"
 #include "doomtype.h"
+#include "g_game.h"
 #include "i_printf.h"
 #include "m_array.h"
 #include "m_misc.h"
@@ -77,6 +78,7 @@ typedef struct
 {
     md5_digest_t checksum;
     option_t *options;
+    demo_version_t complevel;
 } comp_record_t;
 
 static comp_record_t *comp_database;
@@ -125,6 +127,18 @@ void G_ParseCompDatabase(void)
             I_Printf(VB_ERROR, "COMPDB: wrong key %s", md5);
             continue;
         }
+
+        record.complevel = DV_MBF21;
+        const char *complevel = JS_GetStringValue(level, "complevel");
+        if (complevel)
+        {
+            demo_version_t new_complevel = G_GetNamedComplevel(complevel);
+            if (new_complevel != DV_NONE)
+            {
+                record.complevel = new_complevel;
+            }
+        }
+
         json_t *js_options = JS_GetObject(level, "options");
         json_t *js_option = NULL;
         JS_ArrayForEach(js_option, js_options)
@@ -184,19 +198,23 @@ static void GetLevelCheckSum(int lump, md5_checksum_t* cksum)
 
 void G_ApplyLevelCompatibility(int lump)
 {
-    if (demorecording || demoplayback || netgame || !mbf21)
-    {
-        return;
-    }
-
     static boolean restore_comp;
     static int old_comp[COMP_TOTAL];
 
     if (restore_comp)
     {
+        if (demo_version != DV_MBF21)
+        {
+            demo_version = DV_MBF21;
+            G_ReloadDefaults(true);
+        }
         memcpy(comp, old_comp, sizeof(*comp));
         restore_comp = false;
     }
+    else if (demorecording || demoplayback || netgame || !mbf21)
+    {
+        return;
+    }
 
     md5_checksum_t cksum;
 
@@ -212,6 +230,20 @@ void G_ApplyLevelCompatibility(int lump)
             memcpy(old_comp, comp, sizeof(*comp));
             restore_comp = true;
 
+            demo_version_t new_demover = record->complevel;
+            if (new_demover != DV_MBF21)
+            {
+                demo_version = new_demover;
+                G_ReloadDefaults(true);
+                I_Printf(VB_INFO, "Automatically setting compatibility level \"%s\"",
+                         G_GetCurrentComplevelName());
+            }
+
+            if (!mbf21)
+            {
+                return;
+            }
+
             option_t *option;
             array_foreach(option, record->options)
             {