diff --git a/lexer/token_kind.h b/lexer/token_kind.h
index 86070ce35c5c..4e76ad8d6f3c 100644
--- a/lexer/token_kind.h
+++ b/lexer/token_kind.h
@@ -13,6 +13,8 @@
 namespace Carbon {
 
 class TokenKind {
+  // Note that this must be declared earlier in the class so that its type can
+  // be used, for example in the conversion operator.
   enum class KindEnum : int8_t {
 #define CARBON_TOKEN(TokenName) TokenName,
 #include "lexer/token_registry.def"
diff --git a/lexer/tokenized_buffer.h b/lexer/tokenized_buffer.h
index fa8c18521913..2ca8233a75db 100644
--- a/lexer/tokenized_buffer.h
+++ b/lexer/tokenized_buffer.h
@@ -274,15 +274,15 @@ class TokenizedBuffer {
   // Specifies minimum widths to use when printing a token's fields via
   // `printToken`.
   struct PrintWidths {
+    // Widens `this` to the maximum of `this` and `new_width` for each
+    // dimension.
+    void Widen(const PrintWidths& new_width);
+
     int index;
     int kind;
     int column;
     int line;
     int indent;
-
-    // Widens `this` to the maximum of `this` and `new_width` for each
-    // dimension.
-    void Widen(const PrintWidths& new_width);
   };
 
   struct TokenInfo {
diff --git a/lexer/tokenized_buffer_test_helpers.h b/lexer/tokenized_buffer_test_helpers.h
index ebc099472f13..039fd8fd470b 100644
--- a/lexer/tokenized_buffer_test_helpers.h
+++ b/lexer/tokenized_buffer_test_helpers.h
@@ -24,13 +24,6 @@ inline void PrintTo(const TokenizedBuffer& buffer, std::ostream* output) {
 namespace Testing {
 
 struct ExpectedToken {
-  TokenKind kind;
-  int line = -1;
-  int column = -1;
-  int indent_column = -1;
-  bool recovery = false;
-  llvm::StringRef text = "";
-
   friend auto operator<<(std::ostream& output, const ExpectedToken& expected)
       -> std::ostream& {
     output << "\ntoken: { kind: '" << expected.kind.Name().str();
@@ -52,6 +45,13 @@ struct ExpectedToken {
     output << " }";
     return output;
   }
+
+  TokenKind kind;
+  int line = -1;
+  int column = -1;
+  int indent_column = -1;
+  bool recovery = false;
+  llvm::StringRef text = "";
 };
 
 // TODO: Consider rewriting this into a `TokenEq` matcher which is used inside
diff --git a/parser/parse_node_kind.h b/parser/parse_node_kind.h
index debcd67421ad..c9c1eec4a47f 100644
--- a/parser/parse_node_kind.h
+++ b/parser/parse_node_kind.h
@@ -24,6 +24,13 @@ namespace Carbon {
 // member functions. These instances are designed specifically to be usable in
 // `case` labels of `switch` statements just like an enumerator would.
 class ParseNodeKind {
+  // Note that this must be declared earlier in the class so that its type can
+  // be used, for example in the conversion operator.
+  enum class KindEnum : uint8_t {
+#define CARBON_PARSE_NODE_KIND(Name) Name,
+#include "parser/parse_node_kind.def"
+  };
+
  public:
   // The formatting for this macro is weird due to a `clang-format` bug. See
   // https://bugs.llvm.org/show_bug.cgi?id=48320 for details.
@@ -47,20 +54,15 @@ class ParseNodeKind {
   // Gets a friendly name for the token for logging or debugging.
   [[nodiscard]] auto GetName() const -> llvm::StringRef;
 
- private:
-  enum class KindEnum : uint8_t {
-#define CARBON_PARSE_NODE_KIND(Name) Name,
-#include "parser/parse_node_kind.def"
-  };
-
-  constexpr explicit ParseNodeKind(KindEnum k) : kind(k) {}
-
   // Enable conversion to our private enum, including in a `constexpr` context,
   // to enable usage in `switch` and `case`. The enum remains private and
   // nothing else should be using this.
   // NOLINTNEXTLINE(google-explicit-constructor)
   constexpr operator KindEnum() const { return kind; }
 
+ private:
+  constexpr explicit ParseNodeKind(KindEnum k) : kind(k) {}
+
   KindEnum kind;
 };
 
diff --git a/parser/parse_tree.h b/parser/parse_tree.h
index 8a601fcdcbb7..edccd14bd8d3 100644
--- a/parser/parse_tree.h
+++ b/parser/parse_tree.h
@@ -140,6 +140,10 @@ class ParseTree {
   // The in-memory representation of data used for a particular node in the
   // tree.
   struct NodeImpl {
+    explicit NodeImpl(ParseNodeKind k, TokenizedBuffer::Token t,
+                      int subtree_size_arg)
+        : kind(k), token(t), subtree_size(subtree_size_arg) {}
+
     // The kind of this node. Note that this is only a single byte.
     ParseNodeKind kind;
 
@@ -179,10 +183,6 @@ class ParseTree {
     // This field should always be a positive integer as at least this node is
     // part of its subtree.
     int32_t subtree_size;
-
-    explicit NodeImpl(ParseNodeKind k, TokenizedBuffer::Token t,
-                      int subtree_size_arg)
-        : kind(k), token(t), subtree_size(subtree_size_arg) {}
   };
 
   static_assert(sizeof(NodeImpl) == 12,
@@ -301,9 +301,9 @@ class ParseTree::PostorderIterator
  private:
   friend class ParseTree;
 
-  Node node;
-
   explicit PostorderIterator(Node n) : node(n) {}
+
+  Node node;
 };
 
 // A forward iterator across the silbings at a particular level in the parse
@@ -343,12 +343,12 @@ class ParseTree::SiblingIterator
  private:
   friend class ParseTree;
 
+  explicit SiblingIterator(const ParseTree& tree_arg, Node n)
+      : tree(&tree_arg), node(n) {}
+
   const ParseTree* tree;
 
   Node node;
-
-  explicit SiblingIterator(const ParseTree& tree_arg, Node n)
-      : tree(&tree_arg), node(n) {}
 };
 
 }  // namespace Carbon
diff --git a/parser/parser_impl.h b/parser/parser_impl.h
index 95da44e19c19..13729c8d5e14 100644
--- a/parser/parser_impl.h
+++ b/parser/parser_impl.h
@@ -25,12 +25,6 @@ class ParseTree::Parser {
  private:
   struct SubtreeStart;
 
-  ParseTree& tree;
-  TokenizedBuffer& tokens;
-
-  TokenizedBuffer::TokenIterator position;
-  TokenizedBuffer::TokenIterator end;
-
   explicit Parser(ParseTree& tree_arg, TokenizedBuffer& tokens_arg)
       : tree(tree_arg),
         tokens(tokens_arg),
@@ -127,6 +121,12 @@ class ParseTree::Parser {
   // skipping errors, can be parsed, it is returned. There may be parse errors
   // even when a node is returned.
   auto ParseDeclaration() -> llvm::Optional<Node>;
+
+  ParseTree& tree;
+  TokenizedBuffer& tokens;
+
+  TokenizedBuffer::TokenIterator position;
+  TokenizedBuffer::TokenIterator end;
 };
 
 }  // namespace Carbon