diff --git a/searx/engines/pdbe.py b/searx/engines/pdbe.py
index 6dcb56169..a155c02fd 100644
--- a/searx/engines/pdbe.py
+++ b/searx/engines/pdbe.py
@@ -67,7 +67,7 @@ def construct_body(result):
             )
         thumbnail = pdbe_preview_url.format(pdb_id=result['pdb_id'])
     except KeyError:
-        content = None
+        content = ""
         thumbnail = None
 
     # construct url for preview image
diff --git a/searx/results.py b/searx/results.py
index 02b7bb204..f3bac2eb7 100644
--- a/searx/results.py
+++ b/searx/results.py
@@ -357,12 +357,12 @@ def merge_two_infoboxes(origin: LegacyResult, other: LegacyResult):
 def merge_two_main_results(origin: MainResult | LegacyResult, other: MainResult | LegacyResult):
     """Merges the values from ``other`` into ``origin``."""
 
-    if len(other.content) > len(origin.content):
+    if len(other.content or "") > len(origin.content or ""):
         # use content with more text
         origin.content = other.content
 
     # use title with more text
-    if len(other.title) > len(origin.title):
+    if len(other.title or "") > len(origin.title or ""):
         origin.title = other.title
 
     # merge all result's parameters not found in origin