diff --git a/TODO.md b/TODO.md
index 043a2f3..30c860d 100644
--- a/TODO.md
+++ b/TODO.md
@@ -6,8 +6,10 @@
 - [ ] Add factory classes to reduce the amount of class import statements
 - [ ] Add build scripts for producing program binaries
 - [ ] Support exporting to MDict (.MDX) dictionary format
+- [ ] Validate scraped webpages after downloading
+- [ ] Log non-fatal failures to a log file instead of raising exceptions
 - [ ] Support more dictionary websites
-  - [ ] [国語辞典オンライン](https://kokugo.jitenon.jp/)
+  - [x] [国語辞典オンライン](https://kokugo.jitenon.jp/)
   - [ ] [Yoji-Jukugo.com](https://yoji-jukugo.com/)
   - [ ] [実用日本語表現辞典](https://www.weblio.jp/cat/dictionary/jtnhj)
 - [ ] Support more Monokakido dictionaries
diff --git a/bot/crawlers.py b/bot/crawlers/crawlers.py
similarity index 100%
rename from bot/crawlers.py
rename to bot/crawlers/crawlers.py
diff --git a/bot/crawlers/factory.py b/bot/crawlers/factory.py
new file mode 100644
index 0000000..f2af6d1
--- /dev/null
+++ b/bot/crawlers/factory.py
@@ -0,0 +1,18 @@
+from bot.targets import Targets
+
+from bot.crawlers.crawlers import JitenonKokugoCrawler
+from bot.crawlers.crawlers import JitenonYojiCrawler
+from bot.crawlers.crawlers import JitenonKotowazaCrawler
+from bot.crawlers.crawlers import Smk8Crawler
+from bot.crawlers.crawlers import Daijirin2Crawler
+
+
+def new_crawler(target, args):
+    crawler_map = {
+        Targets.JITENON_KOKUGO:   JitenonKokugoCrawler,
+        Targets.JITENON_YOJI:     JitenonYojiCrawler,
+        Targets.JITENON_KOTOWAZA: JitenonKotowazaCrawler,
+        Targets.SMK8:             Smk8Crawler,
+        Targets.DAIJIRIN2:        Daijirin2Crawler,
+    }
+    return crawler_map[target](args)
diff --git a/bot/targets.py b/bot/targets.py
new file mode 100644
index 0000000..3c4c571
--- /dev/null
+++ b/bot/targets.py
@@ -0,0 +1,9 @@
+from enum import Enum
+
+
+class Targets(Enum):
+    JITENON_KOKUGO = "jitenon-kokugo"
+    JITENON_YOJI = "jitenon-yoji"
+    JITENON_KOTOWAZA = "jitenon-kotowaza"
+    SMK8 = "smk8"
+    DAIJIRIN2 = "daijirin2"
diff --git a/jitenbot.py b/jitenbot.py
index be42f5b..950ab16 100644
--- a/jitenbot.py
+++ b/jitenbot.py
@@ -18,11 +18,8 @@ along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 import os
 import argparse
-from bot.crawlers import JitenonKokugoCrawler
-from bot.crawlers import JitenonYojiCrawler
-from bot.crawlers import JitenonKotowazaCrawler
-from bot.crawlers import Smk8Crawler
-from bot.crawlers import Daijirin2Crawler
+from bot.targets import Targets
+from bot.crawlers.factory import new_crawler
 
 
 def directory(d):
@@ -34,14 +31,14 @@ def directory(d):
         return d
 
 
-def parse_args(targets):
+def parse_args(target_names):
     parser = argparse.ArgumentParser(
         prog="jitenbot",
         description="Convert Japanese dictionary files to new formats.",
     )
     parser.add_argument(
         "target",
-        choices=targets,
+        choices=target_names,
         help="name of dictionary to convert"
     )
     parser.add_argument(
@@ -59,16 +56,10 @@ def parse_args(targets):
 
 
 def main():
-    crawlers = {
-        "jitenon-kokugo": JitenonKokugoCrawler,
-        "jitenon-yoji": JitenonYojiCrawler,
-        "jitenon-kotowaza": JitenonKotowazaCrawler,
-        "smk8": Smk8Crawler,
-        "daijirin2": Daijirin2Crawler,
-    }
-    args = parse_args(crawlers.keys())
-    crawler_class = crawlers[args.target]
-    crawler = crawler_class(args)
+    target_names = [x.value for x in Targets]
+    args = parse_args(target_names)
+    selected_target = Targets(args.target)
+    crawler = new_crawler(selected_target, args)
     crawler.collect_pages()
     crawler.read_pages()
     crawler.make_yomichan_dictionary()