diff --git a/mseedpeek/mseedpeek.py b/mseedpeek/mseedpeek.py
index 59d0c286089b7eb03b03f7526feb4154bf1a5dab..8da242ebbce3f2021ed86485db31535226075e61 100644
--- a/mseedpeek/mseedpeek.py
+++ b/mseedpeek/mseedpeek.py
@@ -806,6 +806,7 @@ class MainWindow(QWidget):
         as a thread
         """
 
+        self.run_find_trace = 1
         self.begin_thread("Find Trace",
                           self.find_trace,
                           self.after_find_trace)
@@ -831,6 +832,8 @@ class MainWindow(QWidget):
                 print("Directory Read Error: %s" % e)
 
             for file in listfiles:
+                if not self.run_find_trace:
+                    break
                 if mod(cnt, 5):
                     pass
                 else:
@@ -1494,7 +1497,7 @@ class MainWindow(QWidget):
         """
 
         if title == "Find Trace":
-            self.run_build_trace = 0
+            self.run_find_trace = 0
 
 
 class SliderBox(QGroupBox):