diff --git a/src/chain.h b/src/chain.h
--- a/src/chain.h
+++ b/src/chain.h
@@ -8,6 +8,7 @@
 
 #include "arith_uint256.h"
 #include "consensus/params.h"
+#include "diskblockpos.h"
 #include "pow.h"
 #include "primitives/block.h"
 #include "tinyformat.h"
@@ -30,44 +31,6 @@
  */
 static const int64_t TIMESTAMP_WINDOW = MAX_FUTURE_BLOCK_TIME;
 
-struct CDiskBlockPos {
-    int nFile;
-    unsigned int nPos;
-
-    ADD_SERIALIZE_METHODS;
-
-    template <typename Stream, typename Operation>
-    inline void SerializationOp(Stream &s, Operation ser_action) {
-        READWRITE(VARINT(nFile));
-        READWRITE(VARINT(nPos));
-    }
-
-    CDiskBlockPos() { SetNull(); }
-
-    CDiskBlockPos(int nFileIn, unsigned int nPosIn) {
-        nFile = nFileIn;
-        nPos = nPosIn;
-    }
-
-    friend bool operator==(const CDiskBlockPos &a, const CDiskBlockPos &b) {
-        return (a.nFile == b.nFile && a.nPos == b.nPos);
-    }
-
-    friend bool operator!=(const CDiskBlockPos &a, const CDiskBlockPos &b) {
-        return !(a == b);
-    }
-
-    void SetNull() {
-        nFile = -1;
-        nPos = 0;
-    }
-    bool IsNull() const { return (nFile == -1); }
-
-    std::string ToString() const {
-        return strprintf("CBlockDiskPos(nFile=%i, nPos=%i)", nFile, nPos);
-    }
-};
-
 enum class BlockValidity : uint32_t {
     /**
      * Unused.
diff --git a/src/diskblockpos.h b/src/diskblockpos.h
new file mode 100644
--- /dev/null
+++ b/src/diskblockpos.h
@@ -0,0 +1,51 @@
+// Copyright (c) 2018 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_DISKBLOCKPOS_H
+#define BITCOIN_DISKBLOCKPOS_H
+
+#include "serialize.h"
+#include "tinyformat.h"
+
+#include <string>
+
+struct CDiskBlockPos {
+    int nFile;
+    unsigned int nPos;
+
+    ADD_SERIALIZE_METHODS;
+
+    template <typename Stream, typename Operation>
+    inline void SerializationOp(Stream &s, Operation ser_action) {
+        READWRITE(VARINT(nFile));
+        READWRITE(VARINT(nPos));
+    }
+
+    CDiskBlockPos() { SetNull(); }
+
+    CDiskBlockPos(int nFileIn, unsigned int nPosIn) {
+        nFile = nFileIn;
+        nPos = nPosIn;
+    }
+
+    friend bool operator==(const CDiskBlockPos &a, const CDiskBlockPos &b) {
+        return (a.nFile == b.nFile && a.nPos == b.nPos);
+    }
+
+    friend bool operator!=(const CDiskBlockPos &a, const CDiskBlockPos &b) {
+        return !(a == b);
+    }
+
+    void SetNull() {
+        nFile = -1;
+        nPos = 0;
+    }
+    bool IsNull() const { return (nFile == -1); }
+
+    std::string ToString() const {
+        return strprintf("CBlockDiskPos(nFile=%i, nPos=%i)", nFile, nPos);
+    }
+};
+
+#endif // BITCOIN_DISKBLOCKPOS_H
diff --git a/src/init.cpp b/src/init.cpp
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -17,6 +17,7 @@
 #include "compat/sanity.h"
 #include "config.h"
 #include "consensus/validation.h"
+#include "diskblockpos.h"
 #include "fs.h"
 #include "httprpc.h"
 #include "httpserver.h"
diff --git a/src/test/blockindex_tests.cpp b/src/test/blockindex_tests.cpp
--- a/src/test/blockindex_tests.cpp
+++ b/src/test/blockindex_tests.cpp
@@ -3,6 +3,7 @@
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include "chain.h"
+#include "diskblockpos.h"
 #include "uint256.h"
 
 #include "test/test_bitcoin.h"
diff --git a/src/txdb.h b/src/txdb.h
--- a/src/txdb.h
+++ b/src/txdb.h
@@ -6,10 +6,11 @@
 #ifndef BITCOIN_TXDB_H
 #define BITCOIN_TXDB_H
 
-#include "chain.h"
 #include "blockfileinfo.h"
+#include "chain.h"
 #include "coins.h"
 #include "dbwrapper.h"
+#include "diskblockpos.h"
 
 #include <map>
 #include <string>
diff --git a/src/validation.h b/src/validation.h
--- a/src/validation.h
+++ b/src/validation.h
@@ -12,10 +12,11 @@
 #endif
 
 #include "amount.h"
-#include "chain.h"
 #include "blockfileinfo.h"
+#include "chain.h"
 #include "coins.h"
 #include "consensus/consensus.h"
+#include "diskblockpos.h"
 #include "fs.h"
 #include "protocol.h" // For CMessageHeader::MessageMagic
 #include "script/script_error.h"