diff --git a/gallery_dl/extractor/pixiv.py b/gallery_dl/extractor/pixiv.py
index 7aee39bf..d2dd33a4 100644
--- a/gallery_dl/extractor/pixiv.py
+++ b/gallery_dl/extractor/pixiv.py
@@ -446,16 +446,14 @@ class PixivArtworksExtractor(PixivExtractor):
         if self.sanity_workaround:
             body = self._request_ajax(
                 f"/user/{self.user_id}/profile/all")
-            if not body:
-                return ()
             try:
                 ajax_ids = list(map(int, body["illusts"]))
                 ajax_ids.extend(map(int, body["manga"]))
                 ajax_ids.sort()
             except Exception as exc:
+                self.log.debug("", exc_info=exc)
                 self.log.warning("u%s: Failed to collect artwork IDs "
-                                 "using AJAX API (%s: %s)",
-                                 self.user_id, exc.__class__.__name__, exc)
+                                 "using AJAX API", self.user_id)
             else:
                 works = self._extend_sanity(works, ajax_ids)
 
diff --git a/test/results/pixiv.py b/test/results/pixiv.py
index b0cce7d8..ad6ac4b8 100644
--- a/test/results/pixiv.py
+++ b/test/results/pixiv.py
@@ -102,6 +102,14 @@ __tests__ = (
     },
 },
 
+{
+    "#url"     : "https://www.pixiv.net/en/users/173530/artworks",
+    "#comment" : "Invalid PHPSESSID cookie",
+    "#class"   : pixiv.PixivArtworksExtractor,
+    "#options" : {"cookies": {"PHPSESSID": "12345_aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"}},
+    "#sha1_url": "852c31ad83b6840bacbce824d85f2a997889efb7",
+},
+
 {
     "#url"     : "https://www.pixiv.net/en/users/173530/artworks/%E6%89%8B%E3%81%B6%E3%82%8D",
     "#comment" : "illusts with specific tag",