diff --git a/src/validationinterface.cpp b/src/validationinterface.cpp
index edc4633c012..7991222496b 100644
--- a/src/validationinterface.cpp
+++ b/src/validationinterface.cpp
@@ -16,14 +16,16 @@
 #include <unordered_map>
 #include <utility>
 
-//! The MainSignalsInstance manages a list of shared_ptr<CValidationInterface>
-//! callbacks.
-//!
-//! A std::unordered_map is used to track what callbacks are currently
-//! registered, and a std::list is to used to store the callbacks that are
-//! currently registered as well as any callbacks that are just unregistered
-//! and about to be deleted when they are done executing.
-struct MainSignalsInstance {
+/**
+ * MainSignalsImpl manages a list of shared_ptr<CValidationInterface> callbacks.
+ *
+ * A std::unordered_map is used to track what callbacks are currently
+ * registered, and a std::list is used to store the callbacks that are
+ * currently registered as well as any callbacks that are just unregistered
+ * and about to be deleted when they are done executing.
+ */
+class MainSignalsImpl
+{
 private:
     Mutex m_mutex;
     //! List entries consist of a callback pointer and reference count. The
@@ -40,7 +42,7 @@ public:
     // our own queue here :(
     SingleThreadedSchedulerClient m_schedulerClient;
 
-    explicit MainSignalsInstance(CScheduler& scheduler LIFETIMEBOUND) : m_schedulerClient(scheduler) {}
+    explicit MainSignalsImpl(CScheduler& scheduler LIFETIMEBOUND) : m_schedulerClient(scheduler) {}
 
     void Register(std::shared_ptr<CValidationInterface> callbacks)
     {
@@ -92,7 +94,7 @@ static CMainSignals g_signals;
 void CMainSignals::RegisterBackgroundSignalScheduler(CScheduler& scheduler)
 {
     assert(!m_internals);
-    m_internals = std::make_unique<MainSignalsInstance>(scheduler);
+    m_internals = std::make_unique<MainSignalsImpl>(scheduler);
 }
 
 void CMainSignals::UnregisterBackgroundSignalScheduler()
diff --git a/src/validationinterface.h b/src/validationinterface.h
index ac62f8b467d..a929a3d56bf 100644
--- a/src/validationinterface.h
+++ b/src/validationinterface.h
@@ -17,9 +17,7 @@ class BlockValidationState;
 class CBlock;
 class CBlockIndex;
 struct CBlockLocator;
-class CConnman;
 class CValidationInterface;
-class uint256;
 class CScheduler;
 enum class MemPoolRemovalReason;
 
@@ -177,10 +175,10 @@ protected:
     friend class ValidationInterfaceTest;
 };
 
-struct MainSignalsInstance;
+class MainSignalsImpl;
 class CMainSignals {
 private:
-    std::unique_ptr<MainSignalsInstance> m_internals;
+    std::unique_ptr<MainSignalsImpl> m_internals;
 
     friend void ::RegisterSharedValidationInterface(std::shared_ptr<CValidationInterface>);
     friend void ::UnregisterValidationInterface(CValidationInterface*);