diff --git a/src/PIL/_version.py b/src/PIL/_version.py
index 0467cf184..7db210d63 100644
--- a/src/PIL/_version.py
+++ b/src/PIL/_version.py
@@ -1,2 +1,2 @@
 # Master version for Pillow
-__version__ = '6.0.0'
+__version__ = '6.1.0.dev0'