diff --git a/VERSION b/VERSION
index b95829267c..a91121ce37 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-3.20
+3.21
diff --git a/setup.py b/setup.py
index fd6f486a01..0138c0239b 100644
--- a/setup.py
+++ b/setup.py
@@ -501,7 +501,7 @@ def _single_compile(obj):
 
 setup(
     name='pybullet',
-    version='3.2.0',
+    version='3.2.1',
     description=
     'Official Python Interface for the Bullet Physics SDK specialized for Robotics Simulation and Reinforcement Learning',
     long_description=
diff --git a/src/LinearMath/btSerializer.h b/src/LinearMath/btSerializer.h
index 2dc981454d..22bcac1bea 100644
--- a/src/LinearMath/btSerializer.h
+++ b/src/LinearMath/btSerializer.h
@@ -481,7 +481,7 @@ class btDefaultSerializer : public btSerializer
 
 		buffer[9] = '3';
 		buffer[10] = '2';
-		buffer[11] = '0';
+		buffer[11] = '1';
 	}
 
 	virtual void startSerialization()