diff --git a/doc/astspec.txt b/doc/astspec.txt
index 92212bf8cb..6d44f7f7e2 100644
--- a/doc/astspec.txt
+++ b/doc/astspec.txt
@@ -364,6 +364,7 @@ AST:
     nnkExprColonExpr(nnkIdent("a"), nnkIntLit(1)),
     nnkExprColonExpr(nnkIdent("b"), nnkIntLit(2)),
     nnkExprColonExpr(nnkIdent("c"), nnkIntLit(3)))
+  nnkTupleConstr()
 
 Since the one tuple would be syntactically identical to parentheses
 with an expression in them, the parser expects a trailing comma for