diff --git a/clang/include/clang/AST/DeclTemplate.h b/clang/include/clang/AST/DeclTemplate.h
index a30ae798a99bc..b82f75dd63fa5 100644
--- a/clang/include/clang/AST/DeclTemplate.h
+++ b/clang/include/clang/AST/DeclTemplate.h
@@ -1960,6 +1960,8 @@ class ClassTemplateSpecializationDecl : public CXXRecordDecl,
 
   bool hasStrictPackMatch() const { return StrictPackMatch; }
 
+  void setStrictPackMatch(bool Val) { StrictPackMatch = Val; }
+
   /// Get the point of instantiation (if any), or null if none.
   SourceLocation getPointOfInstantiation() const {
     return PointOfInstantiation;
diff --git a/lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.cpp b/lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.cpp
index 1da8fbe0bcd6d..ecb571b1161bb 100644
--- a/lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.cpp
+++ b/lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.cpp
@@ -1666,6 +1666,12 @@ TypeSystemClang::CreateClassTemplateSpecializationDecl(
   ast.getTypeDeclType(class_template_specialization_decl, nullptr);
   class_template_specialization_decl->setDeclName(
       class_template_decl->getDeclName());
+
+  // FIXME: set to fixed value for now so it's not uninitialized.
+  // One way to determine StrictPackMatch would be
+  // Sema::CheckTemplateTemplateArgument.
+  class_template_specialization_decl->setStrictPackMatch(false);
+
   SetOwningModule(class_template_specialization_decl, owning_module);
   decl_ctx->addDecl(class_template_specialization_decl);