diff --git a/src/txmempool.h b/src/txmempool.h
--- a/src/txmempool.h
+++ b/src/txmempool.h
@@ -30,6 +30,7 @@
 #include <vector>
 
 class CBlockIndex;
+class CChain;
 class CChainState;
 class Config;
 
@@ -53,6 +54,13 @@
     CBlockIndex *maxInputBlock{nullptr};
 };
 
+/**
+ * Test whether the LockPoints height and time are still valid on the current
+ * chain.
+ */
+bool TestLockPointValidity(const CChain &active_chain, const LockPoints *lp)
+    EXCLUSIVE_LOCKS_REQUIRED(cs_main);
+
 struct CompareIteratorById {
     // SFINAE for T where T is either a pointer type (e.g., a txiter) or a
     // reference_wrapper<T> (e.g. a wrapped CTxMemPoolEntry&)
diff --git a/src/txmempool.cpp b/src/txmempool.cpp
--- a/src/txmempool.cpp
+++ b/src/txmempool.cpp
@@ -82,6 +82,25 @@
     const LockPoints &lp;
 };
 
+bool TestLockPointValidity(const CChain &active_chain, const LockPoints *lp) {
+    AssertLockHeld(cs_main);
+    assert(lp);
+    // If there are relative lock times then the maxInputBlock will be set
+    // If there are no relative lock times, the LockPoints don't depend on the
+    // chain
+    if (lp->maxInputBlock) {
+        // Check whether active_chain is an extension of the block at which the
+        // LockPoints calculation was valid.  If not LockPoints are no longer
+        // valid
+        if (!active_chain.Contains(lp->maxInputBlock)) {
+            return false;
+        }
+    }
+
+    // LockPoints still valid
+    return true;
+}
+
 CTxMemPoolEntry::CTxMemPoolEntry(const CTransactionRef &_tx, const Amount fee,
                                  int64_t time, unsigned int entry_height,
                                  bool spends_coinbase, int64_t sigops_count,
diff --git a/src/validation.h b/src/validation.h
--- a/src/validation.h
+++ b/src/validation.h
@@ -470,13 +470,6 @@
 void UpdateCoins(CCoinsViewCache &view, const CTransaction &tx, CTxUndo &txundo,
                  int nHeight);
 
-/**
- * Test whether the LockPoints height and time are still valid on the current
- * chain.
- */
-bool TestLockPointValidity(const CChain &active_chain, const LockPoints *lp)
-    EXCLUSIVE_LOCKS_REQUIRED(cs_main);
-
 /**
  * Check if transaction will be BIP68 final in the next block to be created on
  * top of tip.
diff --git a/src/validation.cpp b/src/validation.cpp
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -156,25 +156,6 @@
 static uint32_t GetNextBlockScriptFlags(const Consensus::Params &params,
                                         const CBlockIndex *pindex);
 
-bool TestLockPointValidity(const CChain &active_chain, const LockPoints *lp) {
-    AssertLockHeld(cs_main);
-    assert(lp);
-    // If there are relative lock times then the maxInputBlock will be set
-    // If there are no relative lock times, the LockPoints don't depend on the
-    // chain
-    if (lp->maxInputBlock) {
-        // Check whether active_chain is an extension of the block at which
-        // the LockPoints calculation was valid. If not LockPoints are no longer
-        // valid.
-        if (!active_chain.Contains(lp->maxInputBlock)) {
-            return false;
-        }
-    }
-
-    // LockPoints still valid
-    return true;
-}
-
 bool CheckSequenceLocks(CBlockIndex *tip, const CCoinsView &coins_view,
                         const CTransaction &tx, int flags, LockPoints *lp,
                         bool useExistingLockPoints) {