diff --git a/gallery_dl/extractor/nijie.py b/gallery_dl/extractor/nijie.py
index 6ee6931a..3839ad37 100644
--- a/gallery_dl/extractor/nijie.py
+++ b/gallery_dl/extractor/nijie.py
@@ -1,6 +1,6 @@
 # -*- coding: utf-8 -*-
 
-# Copyright 2015-2017 Mike Fährmann
+# Copyright 2015-2018 Mike Fährmann
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License version 2 as
@@ -35,6 +35,8 @@ class NijieExtractor(AsynchronousExtractor):
         for image_id in images:
             for image_url, image_data in self.get_image_data(image_id):
                 image_data.update(data)
+                if not image_data["extension"]:
+                    image_data["extension"] = "jpg"
                 yield Message.Url, image_url, image_data
 
     def get_job_metadata(self):
@@ -138,7 +140,9 @@ class NijieImageExtractor(NijieExtractor):
         if 300 <= response.status_code < 400:
             raise exception.NotFoundError("image")
         self.page = response.text
-        self.artist_id = text.extract(self.page, "/nijie_picture/sp/", "_")[0]
+        self.artist_id = text.extract(
+            self.page, "/nijie_picture/sp/", "_")[0] or text.extract(
+            self.page, "/dojin_main/", "_")[0]
         return NijieExtractor.get_job_metadata(self)
 
     def get_image_ids(self):
diff --git a/gallery_dl/extractor/powermanga.py b/gallery_dl/extractor/powermanga.py
index 850bbbdd..a936238e 100644
--- a/gallery_dl/extractor/powermanga.py
+++ b/gallery_dl/extractor/powermanga.py
@@ -1,6 +1,6 @@
 # -*- coding: utf-8 -*-
 
-# Copyright 2015-2017 Mike Fährmann
+# Copyright 2015-2018 Mike Fährmann
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License version 2 as
@@ -26,6 +26,16 @@ class PowermangaMangaExtractor(foolslide.FoolslideMangaExtractor):
     category = "powermanga"
     pattern = foolslide.manga_pattern(r"read\.powermanga\.org")
     test = [("https://read.powermanga.org/series/one_piece/", {
-        "url": "e5e9a64c14ca51a170e14c4b711aaa88fdf7a7aa",
-        "keyword": "1245ab2a730f9129001a4589b1d8615a17dc4a7b",
+        "count": ">= 1",
+        "keyword": {
+            "chapter": int,
+            "chapter_minor": str,
+            "chapter_string": str,
+            "group": "PowerManga",
+            "lang": "en",
+            "language": "English",
+            "manga": "One Piece",
+            "title": str,
+            "volume": int,
+        },
     })]
diff --git a/test/test_extractors.py b/test/test_extractors.py
index bc422cc6..67a9d04a 100644
--- a/test/test_extractors.py
+++ b/test/test_extractors.py
@@ -1,7 +1,7 @@
 #!/usr/bin/env python3
 # -*- coding: utf-8 -*-
 
-# Copyright 2015-2017 Mike Fährmann
+# Copyright 2015-2018 Mike Fährmann
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License version 2 as
@@ -20,6 +20,7 @@ SKIP = {
     # temporary issues
     "chronos",
     "coreimg",
+    "hosturimage",
     "yeet",
 }