diff --git a/clip/model.py b/clip/model.py
index d77561288..954a01f87 100644
--- a/clip/model.py
+++ b/clip/model.py
@@ -158,6 +158,9 @@ def forward(self, x):
         """
 
         def stem(x):
+            """Forward pass through the network stem, applying convolutions, batch normalization, ReLU activations, and
+            average pooling.
+            """
             x = self.relu1(self.bn1(self.conv1(x)))
             x = self.relu2(self.bn2(self.conv2(x)))
             x = self.relu3(self.bn3(self.conv3(x)))