diff --git a/src/pipecat/frames/frames.py b/src/pipecat/frames/frames.py
index 7f0a46efc..6ee7a858c 100644
--- a/src/pipecat/frames/frames.py
+++ b/src/pipecat/frames/frames.py
@@ -657,7 +657,7 @@ class ErrorFrame(SystemFrame):
 
     error: str
     fatal: bool = False
-    source: Optional[FrameProcessor] = None
+    source: Optional["FrameProcessor"] = None
 
     def __str__(self):
         return f"{self.name}(error: {self.error}, fatal: {self.fatal})"