diff --git a/source/duke3d/src/gamedef.cpp b/source/duke3d/src/gamedef.cpp
index 768302b61..50611880e 100644
--- a/source/duke3d/src/gamedef.cpp
+++ b/source/duke3d/src/gamedef.cpp
@@ -5981,6 +5981,7 @@ static void C_AddDefaultDefinitions(void)
         { "GAMEVAR_NORESET",   GAMEVAR_NORESET },
         { "GAMEVAR_PERACTOR",  GAMEVAR_PERACTOR },
         { "GAMEVAR_PERPLAYER", GAMEVAR_PERPLAYER },
+        { "GAMEVAR_SERIALIZE", GAMEVAR_SERIALIZE },
 
         { "MAX_WEAPONS",        MAX_WEAPONS },
         { "MAXSPRITES",         MAXSPRITES },
diff --git a/source/duke3d/src/gamevars.h b/source/duke3d/src/gamevars.h
index 767bf67a9..fa384da44 100644
--- a/source/duke3d/src/gamevars.h
+++ b/source/duke3d/src/gamevars.h
@@ -53,6 +53,7 @@ enum GamevarFlags_t
     GAMEVAR_SPECIAL   = 0x00040000,  // flag for structure member shortcut vars
     GAMEVAR_NOMULTI   = 0x00080000,  // don't attach to multiplayer packets
     GAMEVAR_Q16PTR    = 0x00100000,  // plValues is a pointer to a q16.16
+    GAMEVAR_SERIALIZE = 0x00200000,  // write into permasaves
 
     GAMEVAR_RAWQ16PTR = GAMEVAR_Q16PTR | GAMEVAR_SPECIAL,  // plValues is a pointer to a q16.16 but we don't want conversion
     GAMEVAR_PTR_MASK  = GAMEVAR_INT32PTR | GAMEVAR_INT16PTR | GAMEVAR_Q16PTR | GAMEVAR_RAWQ16PTR,