diff --git a/lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.cpp b/lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.cpp
--- a/lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.cpp
+++ b/lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.cpp
@@ -7571,7 +7571,8 @@
   clang::CXXRecordDecl *cxx_record_decl =
       record_qual_type->getAsCXXRecordDecl();
 
-  if (cxx_record_decl == nullptr)
+  // Bail if no declaration or if the declaration has no definition.
+  if (cxx_record_decl == nullptr || !cxx_record_decl->hasDefinition())
     return nullptr;
 
   clang::QualType method_qual_type(ClangUtil::GetQualType(method_clang_type));