diff --git a/parse_get.go b/parse_get.go
index 8910a3e..6a9cdb2 100644
--- a/parse_get.go
+++ b/parse_get.go
@@ -148,11 +148,16 @@ func (c *Client) handleSSEResponse(req *http.Request, onUpdate ParseResultUpdate
 		return &result, nil
 	}
 
+	var lastEvent string
+	var eventCount int
 	for ev, err := range sse.ScanEvents(resp.Body) {
 		if err != nil {
 			return nil, fmt.Errorf("failed to scan SSE events: %w", err)
 		}
 
+		lastEvent = ev.Name()
+		eventCount++
+
 		// Unmarshal the event data into a ParseResult.
 		var result ParseResult
 		if err := json.Unmarshal(ev.Data(), &result); err != nil {
@@ -182,5 +187,8 @@ func (c *Client) handleSSEResponse(req *http.Request, onUpdate ParseResultUpdate
 		}
 	}
 
-	panic("unreachable")
+	if eventCount == 0 {
+		return nil, fmt.Errorf("SSE stream closed without sending any events")
+	}
+	return nil, fmt.Errorf("SSE stream ended after %d event(s), last event %q, without a terminal event (parse_done or parse_failed)", eventCount, lastEvent)
 }