diff --git a/lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.cpp b/lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.cpp
--- a/lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.cpp
+++ b/lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.cpp
@@ -77,11 +77,23 @@
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Wreturn-type-c-linkage"
 
+// Disable warning C4190: 'LLDBSwigPythonBreakpointCallbackFunction' has
+// C-linkage specified, but returns UDT 'llvm::Expected<bool>' which is
+// incompatible with C
+#if _MSC_VER
+#pragma warning (push)
+#pragma warning (disable : 4190)
+#endif
+
 extern "C" llvm::Expected<bool> LLDBSwigPythonBreakpointCallbackFunction(
     const char *python_function_name, const char *session_dictionary_name,
     const lldb::StackFrameSP &sb_frame,
     const lldb::BreakpointLocationSP &sb_bp_loc, StructuredDataImpl *args_impl);
 
+#if _MSC_VER
+#pragma warning (pop)
+#endif
+
 #pragma clang diagnostic pop
 
 extern "C" bool LLDBSwigPythonWatchpointCallbackFunction(
diff --git a/lldb/unittests/ScriptInterpreter/Python/PythonTestSuite.cpp b/lldb/unittests/ScriptInterpreter/Python/PythonTestSuite.cpp
--- a/lldb/unittests/ScriptInterpreter/Python/PythonTestSuite.cpp
+++ b/lldb/unittests/ScriptInterpreter/Python/PythonTestSuite.cpp
@@ -62,6 +62,14 @@
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Wreturn-type-c-linkage"
 
+// Disable warning C4190: 'LLDBSwigPythonBreakpointCallbackFunction' has
+// C-linkage specified, but returns UDT 'llvm::Expected<bool>' which is
+// incompatible with C
+#if _MSC_VER
+#pragma warning (push)
+#pragma warning (disable : 4190)
+#endif
+
 extern "C" llvm::Expected<bool> LLDBSwigPythonBreakpointCallbackFunction(
     const char *python_function_name, const char *session_dictionary_name,
     const lldb::StackFrameSP &sb_frame,
@@ -70,6 +78,10 @@
   return false;
 }
 
+#if _MSC_VER
+#pragma warning (pop)
+#endif
+
 #pragma clang diagnostic pop
 
 extern "C" bool LLDBSwigPythonWatchpointCallbackFunction(