diff --git a/strix/fix/prepare.py b/strix/fix/prepare.py
index e609dbeb0..c0ea6e241 100644
--- a/strix/fix/prepare.py
+++ b/strix/fix/prepare.py
@@ -61,7 +61,7 @@ class PreparationContext:
     workspace: Path
     candidate: FixCandidateV1
     attempt: int = 0
-    feedback: list[FixPreparationAttempt] = field(default_factory=list)
+    feedback: list[FixPreparationAttempt] = field(default_factory=list[FixPreparationAttempt])
 
 
 RepairAgent = Callable[