diff --git a/src/validationinterface.cpp b/src/validationinterface.cpp
index e8ff1d78e32ac..da2685d771c37 100644
--- a/src/validationinterface.cpp
+++ b/src/validationinterface.cpp
@@ -9,6 +9,7 @@
 #include <consensus/validation.h>
 #include <kernel/chain.h>
 #include <kernel/mempool_entry.h>
+#include <kernel/mempool_removal_reason.h>
 #include <logging.h>
 #include <primitives/block.h>
 #include <primitives/transaction.h>
@@ -19,8 +20,6 @@
 #include <unordered_map>
 #include <utility>
 
-std::string RemovalReasonToString(const MemPoolRemovalReason& r) noexcept;
-
 /**
  * ValidationSignalsImpl manages a list of shared_ptr<CValidationInterface> callbacks.
  *