diff --git a/setup.py b/setup.py
index c9a1289..9d44ad1 100644
--- a/setup.py
+++ b/setup.py
@@ -4,7 +4,7 @@
   name = 'x-clip',
   packages = find_packages(exclude=[]),
   include_package_data = True,
-  version = '0.4.4',
+  version = '0.4.5',
   license='MIT',
   description = 'X-CLIP',
   author = 'Phil Wang',
diff --git a/x_clip/visual_ssl.py b/x_clip/visual_ssl.py
index 3b479f9..c836446 100644
--- a/x_clip/visual_ssl.py
+++ b/x_clip/visual_ssl.py
@@ -116,6 +116,8 @@ def MLP(dim, projection_size, hidden_size = None):
     )
 
 def SimSiamMLP(dim, projection_size, hidden_size = 4096):
+    hidden_size = default(hidden_size, projection_size * 2)
+
     return nn.Sequential(
         nn.Linear(dim, hidden_size, bias = False),
         nn.BatchNorm1d(hidden_size),