diff --git a/jenkins/worker.py b/jenkins/worker.py
index 4ea8d1f..0f84530 100644
--- a/jenkins/worker.py
+++ b/jenkins/worker.py
@@ -40,7 +40,7 @@ class Pattern(object):
     None if no match was found.
     """
     matches = self.regex.findall(text)
-    if matches:
+    if not matches:
       return None
     return matches[-1]