diff --git a/gunicorn/glogging.py b/gunicorn/glogging.py
index eaa82708..d15925fd 100644
--- a/gunicorn/glogging.py
+++ b/gunicorn/glogging.py
@@ -87,6 +87,9 @@ class LazyWriter(object):
     def flush(self):
         self.open().flush()
 
+    def isatty(self):
+        return bool(self.fileobj and self.fileobj.isatty())
+
 class SafeAtoms(dict):
 
     def __init__(self, atoms):
diff --git a/tests/test_005-lazywriter-isatty.py b/tests/test_005-lazywriter-isatty.py
new file mode 100644
index 00000000..50cc71c9
--- /dev/null
+++ b/tests/test_005-lazywriter-isatty.py
@@ -0,0 +1,13 @@
+import sys
+
+from gunicorn.glogging import LazyWriter
+
+
+def test_lazywriter_isatty():
+    orig = sys.stdout
+    sys.stdout = LazyWriter('test.log')
+    try:
+        sys.stdout.isatty()
+    except AttributeError:
+        raise AssertionError("LazyWriter has no attribute 'isatty'")
+    sys.stdout = orig