diff --git a/util/test.py b/util/test.py
index 8e5bc0fb..1f9454b5 100755
--- a/util/test.py
+++ b/util/test.py
@@ -182,6 +182,7 @@ class Test:
 
     # Make sure the stack trace has the right line. Skip over any lines that
     # come from builtin libraries.
+    match = False
     stack_lines = error_lines[line + 1:]
     for stack_line in stack_lines:
       match = STACK_TRACE_PATTERN.search(stack_line)