diff --git a/tools/setup/emoji/build_emoji b/tools/setup/emoji/build_emoji
index 1a8289d675..f63344054d 100755
--- a/tools/setup/emoji/build_emoji
+++ b/tools/setup/emoji/build_emoji
@@ -202,9 +202,14 @@ def dump_emojis(cache_path):
     # type: (str) -> None
     subprocess.call('ttx -v -z extfile -d {} NotoColorEmoji.ttf'.format(EMOJI_DUMP_DIR_PATH), shell=True)
 
-    emoji_map = ujson.load(open('emoji_map.json'))
+    with open('emoji_map.json') as emoji_map_file:
+        emoji_map = ujson.load(emoji_map_file)
+
     code_point_to_fname_map = code_point_to_file_name_map(EMOJI_DUMP_PATH("NotoColorEmoji.ttx"))
-    emoji_data = ujson.load(open(os.path.join(EMOJI_DATA_PATH, 'emoji.json')))
+
+    EMOJI_DATA_FILE_PATH = os.path.join(EMOJI_DATA_PATH, 'emoji.json')
+    with open(EMOJI_DATA_FILE_PATH) as emoji_data_file:
+        emoji_data = ujson.load(emoji_data_file)
     emoji_catalog = generate_emoji_catalog(emoji_data)
 
     UNIFIED_REACTIONS_PATH = os.path.join(ZULIP_PATH, 'zerver', 'management', 'data', 'unified_reactions.json')