diff --git a/VERSION b/VERSION
index be14282b7..dc74c5626 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.5.3
+0.5.3a
diff --git a/synapse/__init__.py b/synapse/__init__.py
index c99cd9653..658574dab 100644
--- a/synapse/__init__.py
+++ b/synapse/__init__.py
@@ -16,4 +16,4 @@
 """ This is a reference implementation of a synapse home server.
 """
 
-__version__ = "0.5.3"
+__version__ = "0.5.3a"