diff --git a/src/index/base.h b/src/index/base.h
--- a/src/index/base.h
+++ b/src/index/base.h
@@ -26,6 +26,13 @@
  */
 class BaseIndex : public CValidationInterface {
 protected:
+    /**
+     * The database stores a block locator of the chain the database is synced
+     * to so that the TxIndex can efficiently determine the point it last
+     * stopped at. A locator is used instead of a simple hash of the chain tip
+     * because blocks and block index entries may not be flushed to disk until
+     * after this database is updated.
+     */
     class DB : public CDBWrapper {
     public:
         DB(const fs::path &path, size_t n_cache_size, bool f_memory = false,
diff --git a/src/index/disktxpos.h b/src/index/disktxpos.h
--- a/src/index/disktxpos.h
+++ b/src/index/disktxpos.h
@@ -5,10 +5,8 @@
 #ifndef BITCOIN_INDEX_DISKTXPOS_H
 #define BITCOIN_INDEX_DISKTXPOS_H
 
-#include <chain.h>
 #include <flatfile.h>
-#include <primitives/block.h>
-#include <primitives/transaction.h>
+#include <serialize.h>
 
 struct CDiskTxPos : public FlatFilePos {
     unsigned int nTxOffset; // after header
diff --git a/src/index/txindex.cpp b/src/index/txindex.cpp
--- a/src/index/txindex.cpp
+++ b/src/index/txindex.cpp
@@ -19,15 +19,7 @@
 
 std::unique_ptr<TxIndex> g_txindex;
 
-/**
- * Access to the txindex database (indexes/txindex/)
- *
- * The database stores a block locator of the chain the database is synced to
- * so that the TxIndex can efficiently determine the point it last stopped at.
- * A locator is used instead of a simple hash of the chain tip because blocks
- * and block index entries may not be flushed to disk until after this database
- * is updated.
- */
+/** Access to the txindex database (indexes/txindex/) */
 class TxIndex::DB : public BaseIndex::DB {
 public:
     explicit DB(size_t n_cache_size, bool f_memory = false,