1 files changed, 18 insertions, 0 deletions
diff --git a/tests/basics/lexer.py b/tests/basics/lexer.py
index 1057c3961b..70a9cce993 100644
--- a/tests/basics/lexer.py
+++ b/tests/basics/lexer.py
@@ -38,3 +38,21 @@ def a(x):
                if x:
                 print(x)
 a(1)
+
+# badly formed hex escape sequences
+try:
+    exec(r"'\x0'")
+except SyntaxError:
+    print("SyntaxError")
+try:
+    exec(r"b'\x0'")
+except SyntaxError:
+    print("SyntaxError")
+try:
+    exec(r"'\u000'")
+except SyntaxError:
+    print("SyntaxError")
+try:
+    exec(r"'\U0000000'")
+except SyntaxError:
+    print("SyntaxError")