diff --git a/src/config.h b/src/config.h
index d6cb2dcce..26939188e 100644
--- a/src/config.h
+++ b/src/config.h
@@ -1,58 +1,58 @@
 // Copyright (c) 2017 Amaury SÉCHET
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #ifndef BITCOIN_CONFIG_H
 #define BITCOIN_CONFIG_H
 
 #include <boost/noncopyable.hpp>
 
 #include <cstdint>
 
 class CChainParams;
 
 class Config : public boost::noncopyable {
 public:
     virtual bool SetMaxBlockSize(uint64_t maxBlockSize) = 0;
     virtual uint64_t GetMaxBlockSize() const = 0;
     virtual bool
     SetBlockPriorityPercentage(int64_t blockPriorityPercentage) = 0;
     virtual uint8_t GetBlockPriorityPercentage() const = 0;
     virtual const CChainParams &GetChainParams() const = 0;
     virtual void SetCashAddrEncoding(bool) = 0;
     virtual bool UseCashAddrEncoding() const = 0;
 };
 
 class GlobalConfig final : public Config {
 public:
     GlobalConfig();
-    bool SetMaxBlockSize(uint64_t maxBlockSize);
-    uint64_t GetMaxBlockSize() const;
-    bool SetBlockPriorityPercentage(int64_t blockPriorityPercentage);
-    uint8_t GetBlockPriorityPercentage() const;
-    const CChainParams &GetChainParams() const;
+    bool SetMaxBlockSize(uint64_t maxBlockSize) override;
+    uint64_t GetMaxBlockSize() const override;
+    bool SetBlockPriorityPercentage(int64_t blockPriorityPercentage) override;
+    uint8_t GetBlockPriorityPercentage() const override;
+    const CChainParams &GetChainParams() const override;
     void SetCashAddrEncoding(bool) override;
     bool UseCashAddrEncoding() const override;
 
 private:
     bool useCashAddr;
 };
 
 // Dummy for subclassing in unittests
 class DummyConfig : public Config {
 public:
     bool SetMaxBlockSize(uint64_t maxBlockSize) override { return false; }
     uint64_t GetMaxBlockSize() const override { return 0; }
     bool SetBlockPriorityPercentage(int64_t blockPriorityPercentage) override {
         return false;
     }
     uint8_t GetBlockPriorityPercentage() const override { return 0; }
     const CChainParams &GetChainParams() const override;
     void SetCashAddrEncoding(bool) override {}
     bool UseCashAddrEncoding() const override { return false; }
 };
 
 // Temporary woraround.
 const Config &GetConfig();
 
 #endif