diff --git a/src/test/radix_tests.cpp b/src/test/radix_tests.cpp
--- a/src/test/radix_tests.cpp
+++ b/src/test/radix_tests.cpp
@@ -14,15 +14,6 @@
 
 BOOST_FIXTURE_TEST_SUITE(radix_tests, BasicTestingSetup)
 
-/**
- * Version of Boost::test prior to 1.64 have issues when dealing with nullptr_t.
- * In order to work around this, we ensure that the null pointers are typed in a
- * way that Boost will like better.
- *
- * TODO: Use nullptr directly once the minimum version of boost is 1.64 or more.
- */
-#define NULLPTR(T) static_cast<T *>(nullptr)
-
 template <typename K> struct TestElement {
     K key;
 
diff --git a/src/test/rcu_tests.cpp b/src/test/rcu_tests.cpp
--- a/src/test/rcu_tests.cpp
+++ b/src/test/rcu_tests.cpp
@@ -134,15 +134,6 @@
     }
 }
 
-/**
- * Version of Boost::test prior to 1.64 have issues when dealing with nullptr_t.
- * In order to work around this, we ensure that the null pointers are typed in a
- * way that Boost will like better.
- *
- * TODO: Use nullptr directly once the minimum version of boost is 1.64 or more.
- */
-#define NULLPTR(T) static_cast<T *>(nullptr)
-
 BOOST_AUTO_TEST_CASE(cleanup_test) {
     RCULock::synchronize();
     BOOST_CHECK(RCUTest::getCleanups().empty());
diff --git a/src/test/test_bitcoin.h b/src/test/test_bitcoin.h
--- a/src/test/test_bitcoin.h
+++ b/src/test/test_bitcoin.h
@@ -16,6 +16,15 @@
 
 #include <boost/thread.hpp>
 
+/**
+ * Version of Boost::test prior to 1.64 have issues when dealing with nullptr_t.
+ * In order to work around this, we ensure that the null pointers are typed in a
+ * way that Boost will like better.
+ *
+ * TODO: Use nullptr directly once the minimum version of boost is 1.64 or more.
+ */
+#define NULLPTR(T) static_cast<T *>(nullptr)
+
 extern uint256 insecure_rand_seed;
 extern FastRandomContext insecure_rand_ctx;