diff --git a/Builds/CMake/CMakeFuncs.cmake b/Builds/CMake/CMakeFuncs.cmake
index c10a5f0e1d..8e3cac4eea 100644
--- a/Builds/CMake/CMakeFuncs.cmake
+++ b/Builds/CMake/CMakeFuncs.cmake
@@ -641,7 +641,7 @@ macro(setup_build_boilerplate)
 
   if (NOT WIN32)
     add_definitions(-D_FILE_OFFSET_BITS=64)
-    append_flags(CMAKE_CXX_FLAGS -frtti -std=c++14 -Wno-invalid-offsetof -Wdeprecated
+    append_flags(CMAKE_CXX_FLAGS -frtti -std=c++14 -Wno-invalid-offsetof -Wdeprecated -Wnon-virtual-dtor
       -DBOOST_COROUTINE_NO_DEPRECATION_WARNING -DBOOST_COROUTINES_NO_DEPRECATION_WARNING)
     add_compile_options(-Wall -Wno-sign-compare -Wno-char-subscripts -Wno-format
       -Wno-unused-local-typedefs -g)
diff --git a/src/beast/extras/beast/unit_test/suite.hpp b/src/beast/extras/beast/unit_test/suite.hpp
index d0ded8b6d4..571a910b64 100644
--- a/src/beast/extras/beast/unit_test/suite.hpp
+++ b/src/beast/extras/beast/unit_test/suite.hpp
@@ -183,6 +183,10 @@ public:
     {
     }
 
+    virtual ~suite() = default;
+    suite(suite const&) = delete;
+    suite& operator=(suite const&) = delete;
+
     /** Invokes the test using the specified runner.
 
         Data members are set up here instead of the constructor as a
diff --git a/src/ripple/beast/clock/basic_seconds_clock.h b/src/ripple/beast/clock/basic_seconds_clock.h
index 6cd42b9be3..441e20da24 100644
--- a/src/ripple/beast/clock/basic_seconds_clock.h
+++ b/src/ripple/beast/clock/basic_seconds_clock.h
@@ -37,6 +37,10 @@ class seconds_clock_worker
 {
 public:
     virtual void sample () = 0;
+    virtual ~seconds_clock_worker() = default;
+    seconds_clock_worker() = default;
+    seconds_clock_worker(seconds_clock_worker const&) = delete;
+    seconds_clock_worker& operator=(seconds_clock_worker const&) = delete;
 };
 
 //------------------------------------------------------------------------------
diff --git a/src/ripple/beast/crypto/secure_erase.h b/src/ripple/beast/crypto/secure_erase.h
index 48280108a7..279fa8748c 100644
--- a/src/ripple/beast/crypto/secure_erase.h
+++ b/src/ripple/beast/crypto/secure_erase.h
@@ -35,6 +35,10 @@ private:
     {
         virtual void operator()(
             void* dest, std::size_t bytes) const = 0;
+        virtual ~base() = default;
+        base() = default;
+        base(base const&) = delete;
+        base& operator=(base const&) = delete;
     };
 
     struct impl : base
diff --git a/src/ripple/beast/insight/impl/StatsDCollector.cpp b/src/ripple/beast/insight/impl/StatsDCollector.cpp
index 4a1ac17b04..89aa9a2cbb 100644
--- a/src/ripple/beast/insight/impl/StatsDCollector.cpp
+++ b/src/ripple/beast/insight/impl/StatsDCollector.cpp
@@ -53,6 +53,10 @@ class StatsDMetricBase : public List <StatsDMetricBase>::Node
 {
 public:
     virtual void do_process () = 0;
+    virtual ~StatsDMetricBase() = default;
+    StatsDMetricBase() = default;
+    StatsDMetricBase(StatsDMetricBase const&) = delete;
+    StatsDMetricBase& operator=(StatsDMetricBase const&) = delete;
 };
 
 //------------------------------------------------------------------------------
diff --git a/src/ripple/beast/utility/PropertyStream.h b/src/ripple/beast/utility/PropertyStream.h
index 6ed47f251e..b9bf1dc147 100644
--- a/src/ripple/beast/utility/PropertyStream.h
+++ b/src/ripple/beast/utility/PropertyStream.h
@@ -282,7 +282,7 @@ private:
 
 public:
     explicit Source (std::string const& name);
-    ~Source ();
+    virtual ~Source ();
 
     Source (Source const&) = delete;
     Source& operator= (Source const&) = delete;
diff --git a/src/ripple/core/impl/Workers.h b/src/ripple/core/impl/Workers.h
index ae67d8ff7e..3ea2716797 100644
--- a/src/ripple/core/impl/Workers.h
+++ b/src/ripple/core/impl/Workers.h
@@ -44,6 +44,11 @@ public:
     /** Called to perform tasks as needed. */
     struct Callback
     {
+        virtual ~Callback () = default;
+        Callback() = default;
+        Callback(Callback const&) = delete;
+        Callback& operator=(Callback const&) = delete;
+
         /** Perform a task.
 
             The call is made on a thread owned by Workers. It is important
diff --git a/src/ripple/nodestore/Manager.h b/src/ripple/nodestore/Manager.h
index c4ccc94a11..eb95b3b223 100644
--- a/src/ripple/nodestore/Manager.h
+++ b/src/ripple/nodestore/Manager.h
@@ -31,6 +31,11 @@ namespace NodeStore {
 class Manager
 {
 public:
+    virtual ~Manager () = default;
+    Manager() = default;
+    Manager(Manager const&) = delete;
+    Manager& operator=(Manager const&) = delete;
+
     /** Returns the instance of the manager singleton. */
     static
     Manager&
diff --git a/src/ripple/nodestore/impl/BatchWriter.h b/src/ripple/nodestore/impl/BatchWriter.h
index 1b7e2c1d6b..57bc486fea 100644
--- a/src/ripple/nodestore/impl/BatchWriter.h
+++ b/src/ripple/nodestore/impl/BatchWriter.h
@@ -43,6 +43,11 @@ public:
     /** This callback does the actual writing. */
     struct Callback
     {
+        virtual ~Callback () = default;
+        Callback() = default;
+        Callback(Callback const&) = delete;
+        Callback& operator=(Callback const&) = delete;
+
         virtual void writeBatch (Batch const& batch) = 0;
     };
 
diff --git a/src/ripple/protocol/InnerObjectFormats.h b/src/ripple/protocol/InnerObjectFormats.h
index c799841283..50b05dd9d2 100755
--- a/src/ripple/protocol/InnerObjectFormats.h
+++ b/src/ripple/protocol/InnerObjectFormats.h
@@ -32,6 +32,10 @@ private:
     void addCommonFields (Item& item);
 
 public:
+    virtual ~InnerObjectFormats () = default;
+    InnerObjectFormats(InnerObjectFormats const&) = delete;
+    InnerObjectFormats& operator=(InnerObjectFormats const&) = delete;
+
     /** Create the object.
         This will load the object will all the known inner object formats.
     */
diff --git a/src/ripple/protocol/KnownFormats.h b/src/ripple/protocol/KnownFormats.h
index 173dcd7d6b..d8d88d9908 100644
--- a/src/ripple/protocol/KnownFormats.h
+++ b/src/ripple/protocol/KnownFormats.h
@@ -87,17 +87,15 @@ public:
 
         Derived classes will load the object will all the known formats.
     */
-    KnownFormats ()
-    {
-    }
+    KnownFormats () = default;
 
     /** Destroy the known formats object.
 
         The defined formats are deleted.
     */
-    ~KnownFormats ()
-    {
-    }
+    virtual ~KnownFormats () = default;
+    KnownFormats(KnownFormats const&) = delete;
+    KnownFormats& operator=(KnownFormats const&) = delete;
 
     /** Retrieve the type for a format specified by name.
 
@@ -180,9 +178,6 @@ protected:
     virtual void addCommonFields (Item& item) = 0;
 
 private:
-    KnownFormats(KnownFormats const&) = delete;
-    KnownFormats& operator=(KnownFormats const&) = delete;
-
     std::vector <std::unique_ptr <Item>> m_formats;
     NameMap m_names;
     TypeMap m_types;
diff --git a/src/ripple/server/Session.h b/src/ripple/server/Session.h
index db0d359567..102b0094c3 100644
--- a/src/ripple/server/Session.h
+++ b/src/ripple/server/Session.h
@@ -42,6 +42,8 @@ class Session
 public:
     Session() = default;
     Session (Session const&) = delete;
+    Session& operator=(Session const&) = delete;
+    virtual ~Session () = default;
 
     /** A user-definable pointer.
         The initial value is always zero.
diff --git a/src/ripple/server/WSSession.h b/src/ripple/server/WSSession.h
index b89e5d3cc4..0cd685a637 100644
--- a/src/ripple/server/WSSession.h
+++ b/src/ripple/server/WSSession.h
@@ -110,6 +110,11 @@ struct WSSession
 {
     std::shared_ptr<void> appDefined;
 
+    virtual ~WSSession () = default;
+    WSSession() = default;
+    WSSession(WSSession const&) = delete;
+    WSSession& operator=(WSSession const&) = delete;
+
     virtual
     void
     run() = 0;