diff --git a/src/Makefile.am b/src/Makefile.am
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -93,6 +93,7 @@
   blockencodings.h \
   blockfileinfo.h \
   blockindexworkcomparator.h \
+  blockvalidity.h \
   cashaddr.h \
   cashaddrenc.h \
   chain.h \
diff --git a/src/blockvalidity.h b/src/blockvalidity.h
new file mode 100644
--- /dev/null
+++ b/src/blockvalidity.h
@@ -0,0 +1,50 @@
+// Copyright (c) 2018 The Bitcoin developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_BLOCKVALIDITY_H
+#define BITCOIN_BLOCKVALIDITY_H
+
+#include <cstdint>
+
+enum class BlockValidity : uint32_t {
+    /**
+     * Unused.
+     */
+    UNKNOWN = 0,
+
+    /**
+     * Parsed, version ok, hash satisfies claimed PoW, 1 <= vtx count <= max,
+     * timestamp not in future.
+     */
+    HEADER = 1,
+
+    /**
+     * All parent headers found, difficulty matches, timestamp >= median
+     * previous, checkpoint. Implies all parents are also at least TREE.
+     */
+    TREE = 2,
+
+    /**
+     * Only first tx is coinbase, 2 <= coinbase input script length <= 100,
+     * transactions valid, no duplicate txids, sigops, size, merkle root.
+     * Implies all parents are at least TREE but not necessarily TRANSACTIONS.
+     * When all parent blocks also have TRANSACTIONS, CBlockIndex::nChainTx will
+     * be set.
+     */
+    TRANSACTIONS = 3,
+
+    /**
+     * Outputs do not overspend inputs, no double spends, coinbase output ok, no
+     * immature coinbase spends, BIP30.
+     * Implies all parents are also at least CHAIN.
+     */
+    CHAIN = 4,
+
+    /**
+     * Scripts & signatures ok. Implies all parents are also at least SCRIPTS.
+     */
+    SCRIPTS = 5,
+};
+
+#endif // BITCOIN_BLOCKVALIDITY_H
diff --git a/src/chain.h b/src/chain.h
--- a/src/chain.h
+++ b/src/chain.h
@@ -7,6 +7,7 @@
 #define BITCOIN_CHAIN_H
 
 #include "arith_uint256.h"
+#include "blockvalidity.h"
 #include "consensus/params.h"
 #include "diskblockpos.h"
 #include "pow.h"
@@ -31,46 +32,6 @@
  */
 static const int64_t TIMESTAMP_WINDOW = MAX_FUTURE_BLOCK_TIME;
 
-enum class BlockValidity : uint32_t {
-    /**
-     * Unused.
-     */
-    UNKNOWN = 0,
-
-    /**
-     * Parsed, version ok, hash satisfies claimed PoW, 1 <= vtx count <= max,
-     * timestamp not in future.
-     */
-    HEADER = 1,
-
-    /**
-     * All parent headers found, difficulty matches, timestamp >= median
-     * previous, checkpoint. Implies all parents are also at least TREE.
-     */
-    TREE = 2,
-
-    /**
-     * Only first tx is coinbase, 2 <= coinbase input script length <= 100,
-     * transactions valid, no duplicate txids, sigops, size, merkle root.
-     * Implies all parents are at least TREE but not necessarily TRANSACTIONS.
-     * When all parent blocks also have TRANSACTIONS, CBlockIndex::nChainTx will
-     * be set.
-     */
-    TRANSACTIONS = 3,
-
-    /**
-     * Outputs do not overspend inputs, no double spends, coinbase output ok, no
-     * immature coinbase spends, BIP30.
-     * Implies all parents are also at least CHAIN.
-     */
-    CHAIN = 4,
-
-    /**
-     * Scripts & signatures ok. Implies all parents are also at least SCRIPTS.
-     */
-    SCRIPTS = 5,
-};
-
 struct BlockStatus {
 private:
     uint32_t status;
diff --git a/src/net_processing.cpp b/src/net_processing.cpp
--- a/src/net_processing.cpp
+++ b/src/net_processing.cpp
@@ -8,6 +8,7 @@
 #include "addrman.h"
 #include "arith_uint256.h"
 #include "blockencodings.h"
+#include "blockvalidity.h"
 #include "chainparams.h"
 #include "config.h"
 #include "consensus/validation.h"
diff --git a/src/rpc/mining.cpp b/src/rpc/mining.cpp
--- a/src/rpc/mining.cpp
+++ b/src/rpc/mining.cpp
@@ -5,6 +5,7 @@
 
 #include "rpc/mining.h"
 #include "amount.h"
+#include "blockvalidity.h"
 #include "chain.h"
 #include "chainparams.h"
 #include "config.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
@@ -2,6 +2,7 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
+#include "blockvalidity.h"
 #include "chain.h"
 #include "diskblockpos.h"
 #include "uint256.h"
diff --git a/src/test/blockstatus_tests.cpp b/src/test/blockstatus_tests.cpp
--- a/src/test/blockstatus_tests.cpp
+++ b/src/test/blockstatus_tests.cpp
@@ -2,6 +2,7 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
+#include "blockvalidity.h"
 #include "chain.h"
 #include "test/test_bitcoin.h"
 
diff --git a/src/validation.h b/src/validation.h
--- a/src/validation.h
+++ b/src/validation.h
@@ -16,6 +16,7 @@
 #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"
diff --git a/src/validation.cpp b/src/validation.cpp
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -8,6 +8,7 @@
 
 #include "arith_uint256.h"
 #include "blockindexworkcomparator.h"
+#include "blockvalidity.h"
 #include "chainparams.h"
 #include "checkpoints.h"
 #include "checkqueue.h"