diff --git a/src/pretalx/api/serializers/speaker.py b/src/pretalx/api/serializers/speaker.py
index 814164702..1e9ae78b3 100644
--- a/src/pretalx/api/serializers/speaker.py
+++ b/src/pretalx/api/serializers/speaker.py
@@ -61,12 +61,12 @@ def get_avatar(obj):
 
     @staticmethod
     def get_avatar_source(obj):
-        if obj.user.has_avatar:
+        if obj.user.has_avatar and obj.user.avatar_source != '':
             return obj.user.avatar_source(event=obj.event)
 
     @staticmethod
     def get_avatar_license(obj):
-        if obj.user.has_avatar:
+        if obj.user.has_avatar and obj.user.avatar_license != '':
             return obj.user.avatar_license(event=obj.event)
 
     @staticmethod