diff --git a/gseapy/enrichr.py b/gseapy/enrichr.py
index 7b29574..1ba7ca7 100644
--- a/gseapy/enrichr.py
+++ b/gseapy/enrichr.py
@@ -292,7 +292,7 @@ def get_results_with_background(
         if not response.ok:
             self._logger.error("Error fetching enrichment results: %s" % self._gs)
 
-        data = response.json()
+        data = response.json(allow_nan=True)
         # Note: missig Overlap column
         colnames = [
             "Rank",