diff --git a/Lib/test/test_syntax.py b/Lib/test/test_syntax.py
index e89d940..91ca1db 100644
--- a/Lib/test/test_syntax.py
+++ b/Lib/test/test_syntax.py
@@ -972,6 +972,14 @@ def func2():
 """
         self._check_error(code, "invalid syntax")
 
+    def test_invalid_line_continuation_left_recursive(self):
+        # Check bpo-42218: SyntaxErrors following left-recursive rules
+        # (t_primary_raw in this case) need to be tested explicitly
+        self._check_error("A.\u018a\\ ",
+                          "unexpected character after line continuation character")
+        self._check_error("A.\u03bc\\\n",
+                          "unexpected EOF while parsing")
+
 def test_main():
     support.run_unittest(SyntaxTestCase)
     from test import test_syntax