diff --git a/polymer/eduke32/build/include/editor.h b/polymer/eduke32/build/include/editor.h
index 30bed4364..5e1c1c7f5 100644
--- a/polymer/eduke32/build/include/editor.h
+++ b/polymer/eduke32/build/include/editor.h
@@ -177,6 +177,7 @@ extern void ExtEditWallData(int16_t wallnum);
 extern void ExtEditSpriteData(int16_t spritenum);
 extern const char *ExtGetSectorType(int32_t lotag);
 
+extern void B_SetBoardFileName(const char *fn);
 extern int32_t LoadBoard(const char *filename, uint32_t flags);
 extern const char *SaveBoard(const char *fn, uint32_t flags);
 extern const char *GetSaveBoardFilename(const char *fn);
diff --git a/polymer/eduke32/build/src/build.c b/polymer/eduke32/build/src/build.c
index 24fca89d9..0f797fa88 100644
--- a/polymer/eduke32/build/src/build.c
+++ b/polymer/eduke32/build/src/build.c
@@ -131,6 +131,11 @@ char *testplay_addparam = 0;
 static char boardfilename[BMAX_PATH], selectedboardfilename[BMAX_PATH];
 //extern char levelname[BMAX_PATH];  // in astub.c   XXX: clean up this mess!!!
 
+void B_SetBoardFileName(const char *fn)
+{
+    Bstrncpyz(boardfilename, fn, BMAX_PATH);
+}
+
 static fnlist_t fnlist;
 static CACHE1D_FIND_REC *finddirshigh=NULL, *findfileshigh=NULL;
 static int32_t currentlist=0;
@@ -523,7 +528,6 @@ int32_t app_main(int32_t argc, const char **argv)
     backgroundidle = 1;
 #endif
 
-    boardfilename[0] = 0;
     for (i=1; i<argc; i++)
     {
         if (argv[i][0] == '-')
@@ -553,9 +557,6 @@ int32_t app_main(int32_t argc, const char **argv)
             }
             continue;
         }
-
-        if (!boardfilename[0])
-            Bstrncpyz(boardfilename, argv[i], BMAX_PATH);
     }
 
     if (boardfilename[0] == 0)
diff --git a/polymer/eduke32/source/astub.c b/polymer/eduke32/source/astub.c
index 3d2d7d2ad..86307bccc 100644
--- a/polymer/eduke32/source/astub.c
+++ b/polymer/eduke32/source/astub.c
@@ -8780,7 +8780,12 @@ static void G_CheckCommandLine(int32_t argc, const char **argv)
             k = Bstrrchr(c,'.');
             if (k)
             {
-                if (!Bstrcasecmp(k,".grp") || !Bstrcasecmp(k,".zip"))
+                if (!Bstrcasecmp(k,".map"))
+                {
+                    B_SetBoardFileName(argv[i++]);
+                    continue;
+                }
+                else if (!Bstrcasecmp(k,".grp") || !Bstrcasecmp(k,".zip"))
                 {
                     COPYARG(i);
                     G_AddGroup(argv[i++]);