diff --git a/src/wagtail_personalisation/adapters.py b/src/wagtail_personalisation/adapters.py
index f8f2466..8d1ada8 100644
--- a/src/wagtail_personalisation/adapters.py
+++ b/src/wagtail_personalisation/adapters.py
@@ -184,13 +184,12 @@ class SessionSegmentsAdapter(BaseSegmentsAdapter):
 
                 result = self._test_rules(segment_rules, self.request,
                                           match_any=segment.match_any)
-
-                if result and segment.is_static and not segment.is_full:
-                    if self.request.user.is_authenticated():
-                        segment.static_users.add(self.request.user)
-
-                if result:
-                    additional_segments.append(segment)
+                if result and segment.randomise_into_segment():
+                    if segment.is_static and not segment.is_full:
+                        if self.request.user.is_authenticated():
+                            segment.static_users.add(self.request.user)
+                    else:
+                        additional_segments.append(segment)
 
         self.set_segments(current_segments + additional_segments)
         self.update_visit_count()