diff --git a/include/clang/AST/DeclTemplate.h b/include/clang/AST/DeclTemplate.h
index 3028c4d..d189900 100644
--- a/include/clang/AST/DeclTemplate.h
+++ b/include/clang/AST/DeclTemplate.h
@@ -577,14 +577,16 @@
 class TemplateArgumentListBuilder {
   llvm::SmallVector<TemplateArgument, 16> Args;
 
+  ASTContext &Context;
 public:
+  TemplateArgumentListBuilder(ASTContext &Context) : Context(Context) { }
+  
   // FIXME: Should use the  index array size.
   size_t size() const { return Args.size(); }
-
   size_t flatSize() const { return Args.size(); }
-    
+
+  void push_back(const TemplateArgument& Arg);
   TemplateArgument *getFlatArgumentList() { return Args.data(); }
-  void push_back(const TemplateArgument& Arg) { Args.push_back(Arg); }
 };
 
 /// \brief A template argument list.
diff --git a/lib/AST/DeclTemplate.cpp b/lib/AST/DeclTemplate.cpp
index fbaaf4d..11b9275 100644
--- a/lib/AST/DeclTemplate.cpp
+++ b/lib/AST/DeclTemplate.cpp
@@ -236,6 +236,19 @@
 }
 
 //===----------------------------------------------------------------------===//
+// TemplateArgumentListBuilder Implementation
+//===----------------------------------------------------------------------===//
+void TemplateArgumentListBuilder::push_back(const TemplateArgument& Arg) {
+  switch (Arg.getKind()) {
+  case TemplateArgument::Type:
+    assert(Arg.getAsType()->isCanonical() && "Type must be canonical!");
+    break;
+  }
+  
+  Args.push_back(Arg);
+}
+
+//===----------------------------------------------------------------------===//
 // TemplateArgumentList Implementation
 //===----------------------------------------------------------------------===//
 TemplateArgumentList::TemplateArgumentList(ASTContext &Context,
diff --git a/lib/Sema/SemaTemplate.cpp b/lib/Sema/SemaTemplate.cpp
index 660f54c..f9176ca 100644
--- a/lib/Sema/SemaTemplate.cpp
+++ b/lib/Sema/SemaTemplate.cpp
@@ -811,7 +811,7 @@
 
   // Check that the template argument list is well-formed for this
   // template.
-  TemplateArgumentListBuilder ConvertedTemplateArgs;
+  TemplateArgumentListBuilder ConvertedTemplateArgs(Context);
   if (CheckTemplateArgumentList(Template, TemplateLoc, LAngleLoc, 
                                 TemplateArgs, NumTemplateArgs, RAngleLoc,
                                 ConvertedTemplateArgs))
@@ -2064,7 +2064,7 @@
 
   // Check that the template argument list is well-formed for this
   // template.
-  TemplateArgumentListBuilder ConvertedTemplateArgs;
+  TemplateArgumentListBuilder ConvertedTemplateArgs(Context);
   if (CheckTemplateArgumentList(ClassTemplate, TemplateNameLoc, LAngleLoc, 
                                 &TemplateArgs[0], TemplateArgs.size(),
                                 RAngleLoc, ConvertedTemplateArgs))
@@ -2268,7 +2268,7 @@
 
   // Check that the template argument list is well-formed for this
   // template.
-  TemplateArgumentListBuilder ConvertedTemplateArgs;
+  TemplateArgumentListBuilder ConvertedTemplateArgs(Context);
   if (CheckTemplateArgumentList(ClassTemplate, TemplateNameLoc, LAngleLoc, 
                                 TemplateArgs.data(), TemplateArgs.size(),
                                 RAngleLoc, ConvertedTemplateArgs))
diff --git a/lib/Sema/SemaTemplateDeduction.cpp b/lib/Sema/SemaTemplateDeduction.cpp
index 59793fe..812b319 100644
--- a/lib/Sema/SemaTemplateDeduction.cpp
+++ b/lib/Sema/SemaTemplateDeduction.cpp
@@ -386,7 +386,7 @@
   
   // FIXME: This is terrible. DeduceTemplateArguments should use a 
   // TemplateArgumentListBuilder directly.
-  TemplateArgumentListBuilder Builder;
+  TemplateArgumentListBuilder Builder(Context);
   for (unsigned I = 0, N = Deduced.size(); I != N; ++I)
     Builder.push_back(Deduced[I]);