diff --git a/pdl/pdl_ast.py b/pdl/pdl_ast.py
index c3ee55bd..878df306 100644
--- a/pdl/pdl_ast.py
+++ b/pdl/pdl_ast.py
@@ -120,8 +120,7 @@ class Block(BaseModel):
 
 
 class FunctionBlock(Block):
-    """Function declaration.
-    """
+    """Function declaration."""
 
     model_config = ConfigDict(extra="forbid")
     kind: Literal[BlockKind.FUNCTION] = BlockKind.FUNCTION
@@ -516,6 +515,7 @@ class EmptyBlock(Block):
 """List of blocks.
 """
 
+
 class Program(RootModel):
     """
     Prompt Declaration Language program (PDL)