diff --git a/Core/ClientSML/src/sml_ClientAgent.cpp b/Core/ClientSML/src/sml_ClientAgent.cpp
index 4054082a78..1188e80812 100644
--- a/Core/ClientSML/src/sml_ClientAgent.cpp
+++ b/Core/ClientSML/src/sml_ClientAgent.cpp
@@ -145,14 +145,14 @@ Agent::Agent(Kernel* pKernel, char const* pName)
 
     m_WorkingMemory.SetAgent(this) ;
 
-    m_pDPI = 0;
+    m_pDPI = nullptr;
 
     ClearError() ;
 }
 
 Agent::~Agent()
 {
-    KillDebugger();
+    KillDebugger(true);
 }
 
 Connection* Agent::GetConnection() const
@@ -1839,11 +1839,14 @@ bool Agent::SpawnDebugger(int port, const char* jarpath)
 #endif // _WIN32
 }
 
-bool Agent::KillDebugger()
+bool Agent::KillDebugger(bool ignoreNonExistent)
 {
     if (!m_pDPI)
     {
-        std::cerr << "KillDebugger: No existing debugger process information" << std::endl;
+        if (!ignoreNonExistent)
+        {
+            std::cerr << "KillDebugger: No existing debugger process information" << std::endl;
+        }
         return false;
     }
     bool successful = false;
@@ -1877,7 +1880,7 @@ void Agent::ClearDebuggerProcessInformation()
     if (m_pDPI)
     {
         delete m_pDPI;
-        m_pDPI = 0;
+        m_pDPI = nullptr;
     }
 }
 
diff --git a/Core/ClientSML/src/sml_ClientAgent.h b/Core/ClientSML/src/sml_ClientAgent.h
index e8b3f25b59..f745d5f887 100644
--- a/Core/ClientSML/src/sml_ClientAgent.h
+++ b/Core/ClientSML/src/sml_ClientAgent.h
@@ -884,8 +884,14 @@ namespace sml
             * @brief Kills the previously spawned debugger. Returns false
             *       if the debugger was never spawned or an OS issue occurs
             *       while killing the process.
-            *************************************************************/
-            bool KillDebugger();
+            * @param ignoreNonExistent if true, do not print a warning if
+            * no debugger process exists to kill. This is useful, for example,
+            * when the client doesn't know if the debugger was ever actually
+            * opened, or whether the user may have closed the window, but wants
+            * to close it just in case for cleanup purposes. Not currently
+            * exposed via SWIG bindings.
+            *************************************************************/
+            bool KillDebugger(bool ignoreNonExistent = false);
 
             /*************************************************************
             * @brief Convert a client-side identifier string to kernel-side.