diff --git a/scrapy/utils/log.py b/scrapy/utils/log.py
index cc2f0b164..51f303216 100644
--- a/scrapy/utils/log.py
+++ b/scrapy/utils/log.py
@@ -145,6 +145,10 @@ class StreamLogger(object):
         for line in buf.rstrip().splitlines():
             self.logger.log(self.log_level, line.rstrip())
 
+    def flush(self):
+        for h in self.logger.handlers:
+            h.flush()
+
 
 class LogCounterHandler(logging.Handler):
     """Record log levels count into a crawler stats"""