diff --git a/vyper/ast/parse.py b/vyper/ast/parse.py
index 7c3f285050..20cc483a63 100644
--- a/vyper/ast/parse.py
+++ b/vyper/ast/parse.py
@@ -196,7 +196,11 @@ def generic_visit(self, node):
             node.lineno = 1
             node.col_offset = 0
             node.end_lineno = len(self.source_lines)
-            node.end_col_offset = len(self.source_lines[-1])
+
+            if len(self.source_lines) > 0:
+                node.end_col_offset = len(self.source_lines[-1])
+            else:
+                node.end_col_offset = 0
 
         adjustments = self._pre_parse_result.adjustments