diff --git a/gallery_dl/extractor/exhentai.py b/gallery_dl/extractor/exhentai.py
index 712575cb..01ba03aa 100644
--- a/gallery_dl/extractor/exhentai.py
+++ b/gallery_dl/extractor/exhentai.py
@@ -219,7 +219,6 @@ class ExhentaiGalleryExtractor(ExhentaiExtractor):
             if self.limits:
                 self._check_limits(data)
             if "/fullimg.php" in url:
-                data["extension"] = ""
                 data["_http_validate"] = _validate_response
             else:
                 data["_http_validate"] = None