diff --git a/src/ast.cpp b/src/ast.cpp
index 106b35939..6afa534f6 100644
--- a/src/ast.cpp
+++ b/src/ast.cpp
@@ -1222,26 +1222,26 @@ struct populator_t {
         visit_stack_.pop_back();
     }
 
-    // Flags controlling parsing.
+    /// Flags controlling parsing.
     parse_tree_flags_t flags_{};
 
-    // Stream of tokens which we consume.
-    token_stream_t tokens_;
-
-    // The type which we are attempting to parse, typically job_list but may be
-    // freestanding_argument_list.
-    const type_t top_type_;
-
-    // If set, we are unwinding due to error recovery.
-    bool unwinding_{false};
-
-    // If set, we have encountered an error.
-    bool any_error_{false};
-
-    // Extra stuff like comment ranges.
+    /// Extra stuff like comment ranges.
     ast_t::extras_t extras_{};
 
-    // A stack containing the nodes whose fields we are visiting.
+    /// Stream of tokens which we consume.
+    token_stream_t tokens_;
+
+    /** The type which we are attempting to parse, typically job_list but may be
+        freestanding_argument_list. */
+    const type_t top_type_;
+
+    /// If set, we are unwinding due to error recovery.
+    bool unwinding_{false};
+
+    /// If set, we have encountered an error.
+    bool any_error_{false};
+
+    /// A stack containing the nodes whose fields we are visiting.
     std::vector<const node_t *> visit_stack_{};
 
     // If non-null, populate with errors.