diff --git a/lib/iris/__init__.py b/lib/iris/__init__.py
index d065597294..46cf779c12 100644
--- a/lib/iris/__init__.py
+++ b/lib/iris/__init__.py
@@ -103,7 +103,7 @@ def callback(cube, field, filename):
 
 
 # Iris revision.
-__version__ = "3.1.dev0"
+__version__ = "3.2.dev0"
 
 # Restrict the names imported when using "from iris import *"
 __all__ = [