diff --git a/src/app/cmdoptions.cpp b/src/app/cmdoptions.cpp
index 0b993c3a6..45f9cee6f 100644
--- a/src/app/cmdoptions.cpp
+++ b/src/app/cmdoptions.cpp
@@ -134,11 +134,6 @@ namespace
         }
     };
 
-    bool operator==(const QString &arg, const BoolOption &option)
-    {
-        return (option == arg);
-    }
-
     // Option with string value. May not have a shortcut
     struct StringOption : protected Option
     {
@@ -181,11 +176,6 @@ namespace
         }
     };
 
-    bool operator==(const QString &arg, const StringOption &option)
-    {
-        return (option == arg);
-    }
-
     // Option with integer value. May not have a shortcut
     class IntOption : protected StringOption
     {
@@ -233,11 +223,6 @@ namespace
         }
     };
 
-    bool operator==(const QString &arg, const IntOption &option)
-    {
-        return (option == arg);
-    }
-
     // Option that is explicitly set to true or false, and whose value is undefined when unspecified.
     // May not have a shortcut.
     class TriStateBoolOption : protected Option
@@ -316,11 +301,6 @@ namespace
         bool m_defaultValue;
     };
 
-    bool operator==(const QString &arg, const TriStateBoolOption &option)
-    {
-        return (option == arg);
-    }
-
     constexpr const BoolOption SHOW_HELP_OPTION {"help", 'h'};
     constexpr const BoolOption SHOW_VERSION_OPTION {"version", 'v'};
 #if defined(DISABLE_GUI) && !defined(Q_OS_WIN)
diff --git a/src/base/bittorrent/infohash.cpp b/src/base/bittorrent/infohash.cpp
index 1a6035353..9558c4209 100644
--- a/src/base/bittorrent/infohash.cpp
+++ b/src/base/bittorrent/infohash.cpp
@@ -120,8 +120,3 @@ bool BitTorrent::operator==(const BitTorrent::InfoHash &left, const BitTorrent::
 {
     return (static_cast<InfoHash::WrappedType>(left) == static_cast<InfoHash::WrappedType>(right));
 }
-
-bool BitTorrent::operator!=(const BitTorrent::InfoHash &left, const BitTorrent::InfoHash &right)
-{
-    return !(left == right);
-}
diff --git a/src/base/bittorrent/infohash.h b/src/base/bittorrent/infohash.h
index fa033d0ae..fbf6b8f95 100644
--- a/src/base/bittorrent/infohash.h
+++ b/src/base/bittorrent/infohash.h
@@ -90,7 +90,6 @@ namespace BitTorrent
     std::size_t qHash(const TorrentID &key, std::size_t seed = 0);
 
     bool operator==(const InfoHash &left, const InfoHash &right);
-    bool operator!=(const InfoHash &left, const InfoHash &right);
 }
 
 Q_DECLARE_METATYPE(BitTorrent::TorrentID)
diff --git a/src/base/bittorrent/tracker.cpp b/src/base/bittorrent/tracker.cpp
index eb6f5606b..6da1321cd 100644
--- a/src/base/bittorrent/tracker.cpp
+++ b/src/base/bittorrent/tracker.cpp
@@ -135,11 +135,6 @@ namespace BitTorrent
         return (left.uniqueID() == right.uniqueID());
     }
 
-    bool operator!=(const Peer &left, const Peer &right)
-    {
-        return !(left == right);
-    }
-
     std::size_t qHash(const Peer &key, const std::size_t seed)
     {
         return qHash(key.uniqueID(), seed);
diff --git a/src/base/bittorrent/tracker.h b/src/base/bittorrent/tracker.h
index 6a54ca3a9..892c5f3e2 100644
--- a/src/base/bittorrent/tracker.h
+++ b/src/base/bittorrent/tracker.h
@@ -64,7 +64,6 @@ namespace BitTorrent
     };
 
     bool operator==(const Peer &left, const Peer &right);
-    bool operator!=(const Peer &left, const Peer &right);
     std::size_t qHash(const Peer &key, std::size_t seed = 0);
 
     // *Basic* Bittorrent tracker implementation
diff --git a/src/base/digest32.h b/src/base/digest32.h
index 11c0c314b..5fdace840 100644
--- a/src/base/digest32.h
+++ b/src/base/digest32.h
@@ -144,12 +144,6 @@ bool operator==(const Digest32<N> &left, const Digest32<N> &right)
             == static_cast<typename Digest32<N>::UnderlyingType>(right));
 }
 
-template <int N>
-bool operator!=(const Digest32<N> &left, const Digest32<N> &right)
-{
-    return !(left == right);
-}
-
 template <int N>
 bool operator<(const Digest32<N> &left, const Digest32<N> &right)
 {
diff --git a/src/base/indexrange.h b/src/base/indexrange.h
index 65129f5ea..37931f791 100644
--- a/src/base/indexrange.h
+++ b/src/base/indexrange.h
@@ -107,11 +107,6 @@ public:
             return (*left == *right);
         }
 
-        friend constexpr bool operator!=(const Iterator &left, const Iterator &right)
-        {
-            return !(left == right);
-        }
-
     private:
         IndexType m_index;
     };
diff --git a/src/base/net/proxyconfigurationmanager.cpp b/src/base/net/proxyconfigurationmanager.cpp
index 00bc7cedd..4494280d4 100644
--- a/src/base/net/proxyconfigurationmanager.cpp
+++ b/src/base/net/proxyconfigurationmanager.cpp
@@ -41,11 +41,6 @@ bool Net::operator==(const ProxyConfiguration &left, const ProxyConfiguration &r
             && (left.hostnameLookupEnabled == right.hostnameLookupEnabled);
 }
 
-bool Net::operator!=(const ProxyConfiguration &left, const ProxyConfiguration &right)
-{
-    return !(left == right);
-}
-
 using namespace Net;
 
 ProxyConfigurationManager *ProxyConfigurationManager::m_instance = nullptr;
diff --git a/src/base/net/proxyconfigurationmanager.h b/src/base/net/proxyconfigurationmanager.h
index 5444fb193..41521823d 100644
--- a/src/base/net/proxyconfigurationmanager.h
+++ b/src/base/net/proxyconfigurationmanager.h
@@ -57,7 +57,6 @@ namespace Net
         bool hostnameLookupEnabled = true;
     };
     bool operator==(const ProxyConfiguration &left, const ProxyConfiguration &right);
-    bool operator!=(const ProxyConfiguration &left, const ProxyConfiguration &right);
 
     class ProxyConfigurationManager final : public QObject
     {
diff --git a/src/base/path.cpp b/src/base/path.cpp
index 75bf074ed..2ed951773 100644
--- a/src/base/path.cpp
+++ b/src/base/path.cpp
@@ -342,11 +342,6 @@ bool operator==(const Path &lhs, const Path &rhs)
     return (lhs.data().compare(rhs.data(), CASE_SENSITIVITY) == 0);
 }
 
-bool operator!=(const Path &lhs, const Path &rhs)
-{
-    return !(lhs == rhs);
-}
-
 Path operator/(const Path &lhs, const Path &rhs)
 {
     if (rhs.isEmpty())
diff --git a/src/base/path.h b/src/base/path.h
index 16bf51f71..4501e2668 100644
--- a/src/base/path.h
+++ b/src/base/path.h
@@ -95,7 +95,6 @@ private:
 Q_DECLARE_METATYPE(Path)
 
 bool operator==(const Path &lhs, const Path &rhs);
-bool operator!=(const Path &lhs, const Path &rhs);
 Path operator+(const Path &lhs, QStringView rhs);
 
 QDataStream &operator<<(QDataStream &out, const Path &path);
diff --git a/src/base/rss/rss_autodownloadrule.cpp b/src/base/rss/rss_autodownloadrule.cpp
index 8caff1037..b4637cf43 100644
--- a/src/base/rss/rss_autodownloadrule.cpp
+++ b/src/base/rss/rss_autodownloadrule.cpp
@@ -167,11 +167,6 @@ namespace RSS
         return (left.m_dataPtr == right.m_dataPtr) // optimization
                 || (*(left.m_dataPtr) == *(right.m_dataPtr));
     }
-
-    bool operator!=(const AutoDownloadRule &left, const AutoDownloadRule &right)
-    {
-        return !(left == right);
-    }
 }
 
 using namespace RSS;
diff --git a/src/base/rss/rss_autodownloadrule.h b/src/base/rss/rss_autodownloadrule.h
index 9e5449bc6..ff54b5faf 100644
--- a/src/base/rss/rss_autodownloadrule.h
+++ b/src/base/rss/rss_autodownloadrule.h
@@ -108,6 +108,4 @@ namespace RSS
 
         QSharedDataPointer<AutoDownloadRuleData> m_dataPtr;
     };
-
-    bool operator!=(const AutoDownloadRule &left, const AutoDownloadRule &right);
 }
diff --git a/src/base/utils/version.h b/src/base/utils/version.h
index 98bff202f..ba2618a7b 100644
--- a/src/base/utils/version.h
+++ b/src/base/utils/version.h
@@ -124,13 +124,12 @@ namespace Utils
             return res;
         }
 
-        // TODO: remove manually defined operators and use compiler generated `operator<=>()` in C++20
-        friend bool operator==(const ThisType &left, const ThisType &right)
+        friend constexpr bool operator==(const ThisType &left, const ThisType &right)
         {
             return (left.m_components == right.m_components);
         }
 
-        friend bool operator<(const ThisType &left, const ThisType &right)
+        friend constexpr bool operator<(const ThisType &left, const ThisType &right)
         {
             return (left.m_components < right.m_components);
         }
@@ -159,12 +158,6 @@ namespace Utils
         std::array<int, N> m_components {{}};
     };
 
-    template <int N, int Mandatory>
-    constexpr bool operator!=(const Version<N, Mandatory> &left, const Version<N, Mandatory> &right)
-    {
-        return !(left == right);
-    }
-
     template <int N, int Mandatory>
     constexpr bool operator>(const Version<N, Mandatory> &left, const Version<N, Mandatory> &right)
     {
diff --git a/src/gui/properties/peerlistwidget.cpp b/src/gui/properties/peerlistwidget.cpp
index afae06d64..9f6b37b08 100644
--- a/src/gui/properties/peerlistwidget.cpp
+++ b/src/gui/properties/peerlistwidget.cpp
@@ -67,12 +67,9 @@ struct PeerEndpoint
 {
     BitTorrent::PeerAddress address;
     QString connectionType; // matches return type of `PeerInfo::connectionType()`
-};
 
-bool operator==(const PeerEndpoint &left, const PeerEndpoint &right)
-{
-    return (left.address == right.address) && (left.connectionType == right.connectionType);
-}
+    friend bool operator==(const PeerEndpoint &left, const PeerEndpoint &right) = default;
+};
 
 std::size_t qHash(const PeerEndpoint &peerEndpoint, const std::size_t seed = 0)
 {