diff --git a/src/w_wad.c b/src/w_wad.c
index 1df2eacc7..00bdb7183 100644
--- a/src/w_wad.c
+++ b/src/w_wad.c
@@ -580,7 +580,7 @@ static lumpinfo_t* ResGetLumpsZip (FILE* handle, UINT16* nlmp)
 			return NULL;
 		}
 
-		lump_p->position = zentry->offset + zentry->namelen + zentry->xtralen + sizeof(zlentry_t);
+		lump_p->position = zentry->offset + zentry->namelen + sizeof(zlentry_t);
 		lump_p->disksize = zentry->compsize;
 		lump_p->size = zentry->size;
 
@@ -629,6 +629,15 @@ static lumpinfo_t* ResGetLumpsZip (FILE* handle, UINT16* nlmp)
 			lump_p->compression = CM_UNSUPPORTED;
 			break;
 		}
+
+		// skip and ignore comments/extra fields
+		if (fseek(handle, zentry->xtralen + zentry->commlen, SEEK_CUR) != 0)
+		{
+			CONS_Alert(CONS_ERROR, "Central directory %d is corrupt (%02x%02x%02x%02x)\n", i, zentry->signature[0], zentry->signature[1], zentry->signature[2], zentry->signature[3]);
+			Z_Free(lumpinfo);
+			free(zentries);
+			return NULL;
+		}
 	}
 
 	free(zentries);