diff --git a/Lib/test/test_grammar.py b/Lib/test/test_grammar.py
index 69e1980..14ce7e4 100644
--- a/Lib/test/test_grammar.py
+++ b/Lib/test/test_grammar.py
@@ -747,6 +747,8 @@
 
         x = `x`
         x = `1 or 2 or 3`
+        self.assertEqual(`1,2`, '(1, 2)')
+
         x = x
         x = 'x'
         x = 123
diff --git a/Misc/NEWS b/Misc/NEWS
index 2ed9371..0527d83 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -12,6 +12,8 @@
 Core and builtins
 -----------------
 
+- Bug #1588287: fix invalid assertion for `1,2` in debug builds.
+
 - Bug #1576657: when setting a KeyError for a tuple key, make sure that
   the tuple isn't used as the "exception arguments tuple".
 
diff --git a/Python/ast.c b/Python/ast.c
index f490268..dcf7f2b 100644
--- a/Python/ast.c
+++ b/Python/ast.c
@@ -532,6 +532,7 @@
            || TYPE(n) == listmaker
            || TYPE(n) == testlist_gexp
            || TYPE(n) == testlist_safe
+           || TYPE(n) == testlist1
            );
 
     seq = asdl_seq_new((NCH(n) + 1) / 2, c->c_arena);