diff --git a/src/w_wad.c b/src/w_wad.c
index 84487db5b..841fbc498 100644
--- a/src/w_wad.c
+++ b/src/w_wad.c
@@ -2512,7 +2512,7 @@ virtres_t* vres_GetMap(lumpnum_t lumpnum)
 	}
 	else
 	{
-		// Count number of lumps until the end of resource OR up until next "MAPXX" lump.
+		// Count number of lumps until the end of resource OR up until next 0-length lump.
 		lumpnum_t lumppos = lumpnum + 1;
 		lumpnum_t lastlump = wadfiles[WADFILENUM(lumpnum)]->numlumps;
 		// or the end of directory, for PK3 files
@@ -2526,8 +2526,12 @@ virtres_t* vres_GetMap(lumpnum_t lumpnum)
 			free(dirname);
 		}
 		for (i = LUMPNUM(lumppos); i < lastlump; i++, lumppos++, numlumps++)
-			if (memcmp(W_CheckNameForNum(lumppos), "MAP", 3) == 0)
+		{
+			if (W_LumpLength(lumppos) == 0)
+			{
 				break;
+			}
+		}
 		numlumps++;
 
 		vlumps = Z_Malloc(sizeof(virtlump_t)*numlumps, PU_LEVEL, NULL);
@@ -2621,4 +2625,4 @@ void *vres_GetPatch(virtlump_t *vlump, INT32 tag)
 	Patch_CreateGL(patch);
 	return (void *)patch;
 #endif
-}
\ No newline at end of file
+}