diff --git a/app/logical/sources/strategies/nijie.rb b/app/logical/sources/strategies/nijie.rb
index 4490ecfad..3b680131c 100644
--- a/app/logical/sources/strategies/nijie.rb
+++ b/app/logical/sources/strategies/nijie.rb
@@ -62,15 +62,26 @@ module Sources
       end
 
       def image_url
-        return normalize_thumbnails(url) if url =~ IMAGE_URL
+        return to_full_image_url(url) if url.match?(IMAGE_URL)
         image_urls.first
       end
 
       def image_urls
-        images = page&.search("div#gallery a > img") || []
-        images.map do |img|
-          normalize_thumbnails("https:" + img.attr("src"))
-        end.uniq
+        images = page&.search("div#gallery a > img").to_a.map do |img|
+          "https:#{img["src"]}"
+        end
+
+        images = [url] if url.match?(IMAGE_URL) && images.empty?
+        images.map(&method(:to_full_image_url)).uniq
+      end
+
+      def preview_url
+        return nil if image_url.blank?
+        to_preview_url(image_url)
+      end
+
+      def preview_urls
+        image_urls.map(&method(:to_preview_url))
       end
 
       def page_url
@@ -116,8 +127,12 @@ module Sources
         DText.from_html(text).strip
       end
 
-      def normalize_thumbnails(x)
-        x.gsub(%r!__rs_\w+/!i, "")
+      def to_full_image_url(x)
+        x.gsub(%r!__rs_\w+/!i, "").gsub(/\Ahttp:/, "https:")
+      end
+
+      def to_preview_url(url)
+        url.gsub(/nijie_picture/, "__rs_l170x170/nijie_picture").gsub(/\Ahttp:/, "https:")
       end
 
       def illust_id
diff --git a/test/test_helpers/download_test_helper.rb b/test/test_helpers/download_test_helper.rb
index 172f8d101..620685256 100644
--- a/test/test_helpers/download_test_helper.rb
+++ b/test/test_helpers/download_test_helper.rb
@@ -19,7 +19,22 @@ module DownloadTestHelper
     assert_rewritten(source, source, referer)
   end
 
+  def assert_http_exists(url, headers: {})
+    res = HTTParty.head(url, Danbooru.config.httparty_options.deep_merge(headers: headers))
+    assert_equal(true, res.success?)
+  end
+
+  def assert_http_status(code, url, headers: {})
+    res = HTTParty.head(url, Danbooru.config.httparty_options.deep_merge(headers: headers))
+    assert_equal(code, res.code)
+  end
+
+  def assert_http_size(size, url, headers: {})
+    res = HTTParty.head(url, Danbooru.config.httparty_options.deep_merge(headers: headers))
+    assert_equal(size, res.content_length)
+  end
+
   def check_ffmpeg
     File.which("ffmpeg") && File.which("mkvmerge")
   end
-end
\ No newline at end of file
+end
diff --git a/test/unit/sources/nijie_test.rb b/test/unit/sources/nijie_test.rb
index be8bef47e..f3a7e60ce 100644
--- a/test/unit/sources/nijie_test.rb
+++ b/test/unit/sources/nijie_test.rb
@@ -43,12 +43,19 @@ module Sources
 
       should "get the image url" do
         assert_equal("https://pic03.nijie.info/nijie_picture/728995_20170505014820_0.jpg", @site.image_url)
+        assert_http_size(132_555, @site.image_url)
       end
 
       should "get the canonical url" do
         assert_equal("https://nijie.info/view.php?id=213043", @site.canonical_url)
       end
 
+      should "get the preview url" do
+        assert_equal("https://pic03.nijie.info/__rs_l170x170/nijie_picture/728995_20170505014820_0.jpg", @site.preview_url)
+        assert_equal([@site.preview_url], @site.preview_urls)
+        assert_http_exists(@site.preview_url)
+      end
+
       should "get the profile" do
         assert_equal("https://nijie.info/members.php?id=728995", @site.profile_url)
       end
@@ -86,7 +93,12 @@ module Sources
       end
 
       should "get the image url" do
-        assert_equal("http://pic03.nijie.info/nijie_picture/728995_20170505014820_0.jpg", @site.image_url)
+        assert_equal("https://pic03.nijie.info/nijie_picture/728995_20170505014820_0.jpg", @site.image_url)
+      end
+
+      should "get the preview urls" do
+        assert_equal("https://pic03.nijie.info/__rs_l170x170/nijie_picture/728995_20170505014820_0.jpg", @site.preview_url)
+        assert_equal([@site.preview_url], @site.preview_urls)
       end
 
       should "get the canonical url" do
@@ -111,6 +123,11 @@ module Sources
         assert_equal("https://pic03.nijie.info/nijie_picture/728995_20170505014820_0.jpg", @site.image_url)
       end
 
+      should "get the preview urls" do
+        assert_equal("https://pic03.nijie.info/__rs_l170x170/nijie_picture/728995_20170505014820_0.jpg", @site.preview_url)
+        assert_equal([@site.preview_url], @site.preview_urls)
+      end
+
       should "get the canonical url" do
         assert_equal("https://nijie.info/view.php?id=213043", @site.canonical_url)
       end
@@ -163,6 +180,9 @@ module Sources
         assert_equal(image_url, site.canonical_url)
         assert_equal("https://nijie.info/members.php?id=236014", site.profile_url)
         assert_nothing_raised { site.to_h }
+
+        assert_http_size(3619, site.image_url)
+        assert_http_exists(site.preview_url)
       end
     end
 
@@ -176,6 +196,7 @@ module Sources
         assert_equal("名無しのチンポップ", site.artist_name)
         assert_equal(site.url, site.image_url)
         assert_equal(6, site.image_urls.size)
+        assert_equal(6, site.preview_urls.size)
       end
     end
 
@@ -197,10 +218,13 @@ module Sources
     context "A deleted work" do
       context "for an image url" do
         should "find the profile url" do
-          site = Sources::Strategies.find("http://pic01.nijie.info/nijie_picture/diff/main/196201_20150201033106_0.jpg")
+          site = Sources::Strategies.find("https://pic01.nijie.info/nijie_picture/diff/main/196201_20150201033106_0.jpg")
 
           assert_nothing_raised { site.to_h }
           assert_equal("https://nijie.info/members.php?id=196201", site.profile_url)
+          assert_equal(site.url, site.image_url)
+          assert_equal([site.url], site.image_urls)
+          assert_equal(1, site.preview_urls.size)
         end
       end
 
@@ -214,7 +238,9 @@ module Sources
           assert_nil(site.artist_commentary_desc)
           assert_nil(site.artist_commentary_title)
           assert_nil(site.image_url)
+          assert_nil(site.preview_url)
           assert_empty(site.image_urls)
+          assert_empty(site.preview_urls)
           assert_empty(site.tags)
           assert_nothing_raised { site.to_h }
         end