diff --git a/ptpython/python_input.py b/ptpython/python_input.py
index 975d3d9..b177364 100644
--- a/ptpython/python_input.py
+++ b/ptpython/python_input.py
@@ -1116,4 +1116,5 @@ def pre_run(
                     return result
             except KeyboardInterrupt:
                 # Abort - try again.
+                self.signatures = []
                 self.default_buffer.document = Document()