diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index da064534c25d9..0aa899817f3ea 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -567,6 +567,7 @@ Bug Fixes to C++ Support
 - Fix a crash when extracting unavailable member type from alias in template deduction. (#GH165560)
 - Fix incorrect diagnostics for lambdas with init-captures inside braced initializers. (#GH163498)
 - Fixed spurious diagnoses of certain nested lambda expressions. (#GH149121) (#GH156579)
+- Fix the result of ``__is_pointer_interconvertible_base_of`` when arguments are qualified and passed via template parameters. (#GH135273)
 
 Bug Fixes to AST Handling
 ^^^^^^^^^^^^^^^^^^^^^^^^^
diff --git a/clang/include/clang/AST/CanonicalType.h b/clang/include/clang/AST/CanonicalType.h
index 87bbd7b5d885d..b46fc8f50fa23 100644
--- a/clang/include/clang/AST/CanonicalType.h
+++ b/clang/include/clang/AST/CanonicalType.h
@@ -213,7 +213,8 @@ inline bool operator!=(CanQual<T> x, CanQual<U> y) {
 using CanQualType = CanQual<Type>;
 
 inline CanQualType Type::getCanonicalTypeUnqualified() const {
-  return CanQualType::CreateUnsafe(getCanonicalTypeInternal());
+  return CanQualType::CreateUnsafe(
+      getCanonicalTypeInternal().getUnqualifiedType());
 }
 
 inline const StreamingDiagnostic &operator<<(const StreamingDiagnostic &DB,
diff --git a/clang/test/SemaCXX/type-traits.cpp b/clang/test/SemaCXX/type-traits.cpp
index 9ef44d0346b48..561c9ca8286b9 100644
--- a/clang/test/SemaCXX/type-traits.cpp
+++ b/clang/test/SemaCXX/type-traits.cpp
@@ -1812,6 +1812,11 @@ union Union {};
 union UnionIncomplete;
 struct StructIncomplete; // #StructIncomplete
 
+#if __cplusplus >= 201402L
+template<class _Base, class _Derived>
+inline constexpr bool IsPointerInterconvertibleBaseOfV = __is_pointer_interconvertible_base_of(_Base, _Derived);
+#endif
+
 void is_pointer_interconvertible_base_of(int n)
 {
   static_assert(__is_pointer_interconvertible_base_of(Base, Derived));
@@ -1880,6 +1885,11 @@ void is_pointer_interconvertible_base_of(int n)
   static_assert(!__is_pointer_interconvertible_base_of(void(&)(int), void(&)(char)));
   static_assert(!__is_pointer_interconvertible_base_of(void(*)(int), void(*)(int)));
   static_assert(!__is_pointer_interconvertible_base_of(void(*)(int), void(*)(char)));
+
+#if __cplusplus >= 201402L
+  static_assert(IsPointerInterconvertibleBaseOfV<const Base, Base>);
+  static_assert(IsPointerInterconvertibleBaseOfV<const Base, Derived>);
+#endif
 }
 }