diff --git a/scrapy/utils/gz.py b/scrapy/utils/gz.py
index 9984492f0..dc8316d8c 100644
--- a/scrapy/utils/gz.py
+++ b/scrapy/utils/gz.py
@@ -16,6 +16,7 @@ from scrapy.utils.decorators import deprecated
 #   (regression or bug-fix compared to Python 3.4)
 # - read1(), which fetches data before raising EOFError on next call
 #   works here but is only available from Python>=3.3
+@deprecated('GzipFile.read1')
 def read1(gzf, size=-1):
     return gzf.read1(size)