diff --git a/src/tests/utils.py b/src/tests/utils.py
index 4dc02ac5..ae4e70ed 100644
--- a/src/tests/utils.py
+++ b/src/tests/utils.py
@@ -25,6 +25,8 @@ def update(self, frame):
         pass  # TODO
 
     def __bool__(self):
+        if not self.stereo_frames_consistencies:
+            return False
         for consistency in self.stereo_frames_consistencies:
             if not consistency:
                 return False