diff --git a/eris/eris/tools.py b/eris/eris/tools.py
index 546fa61..c806bad 100755
--- a/eris/eris/tools.py
+++ b/eris/eris/tools.py
@@ -335,15 +335,11 @@ def python_coverage(path):
 def _function_body_lines(python_source):
     ranges = []
     class FuncNodeVisitor(ast.NodeVisitor):
-
         def _line_range(self, body):
             return body[0].lineno - 1, body[-1].end_lineno
-
         def visit_FunctionDef(self, node):
             ranges.append(self._line_range(node.body))
-
-        def visit_AsyncFunctionDef(self, node):
-            ranges.append(self._line_range(node.body))
+        visit_AsyncFunctionDef = visit_FunctionDef
     tree = ast.parse(python_source)
     FuncNodeVisitor().visit(tree)
     return ranges