diff --git a/lib/Sema/SemaCast.cpp b/lib/Sema/SemaCast.cpp
index 3f0a1a3..b4e7113 100644
--- a/lib/Sema/SemaCast.cpp
+++ b/lib/Sema/SemaCast.cpp
@@ -1813,10 +1813,12 @@
     assert(srcIsPtr && "One type must be a pointer");
     // C++ 5.2.10p4: A pointer can be explicitly converted to any integral
     //   type large enough to hold it; except in Microsoft mode, where the
-    //   integral type size doesn't matter.
+    //   integral type size doesn't matter (except we don't allow bool).
+    bool MicrosoftException = Self.getLangOpts().MicrosoftExt &&
+                              !DestType->isBooleanType();
     if ((Self.Context.getTypeSize(SrcType) >
          Self.Context.getTypeSize(DestType)) &&
-         !Self.getLangOpts().MicrosoftExt) {
+         !MicrosoftException) {
       msg = diag::err_bad_reinterpret_cast_small_int;
       return TC_Failed;
     }
diff --git a/test/Sema/MicrosoftExtensions.c b/test/Sema/MicrosoftExtensions.c
index a66d9a9..5215e72 100644
--- a/test/Sema/MicrosoftExtensions.c
+++ b/test/Sema/MicrosoftExtensions.c
@@ -76,6 +76,9 @@
    short sh = (short)ptr;
    ch = (char)ptr;
    sh = (short)ptr;
+
+   // This is valid ISO C.
+   _Bool b = (_Bool)ptr;
 }
 
 
diff --git a/test/SemaCXX/MicrosoftExtensions.cpp b/test/SemaCXX/MicrosoftExtensions.cpp
index 93a6d30..c0e7a5a 100644
--- a/test/SemaCXX/MicrosoftExtensions.cpp
+++ b/test/SemaCXX/MicrosoftExtensions.cpp
@@ -167,8 +167,14 @@
    short sh = (short)ptr;
    ch = (char)ptr;
    sh = (short)ptr;
-} 
 
+   // These are valid C++.
+   bool b = (bool)ptr;
+   b = static_cast<bool>(ptr);
+
+   // This is bad.
+   b = reinterpret_cast<bool>(ptr); // expected-error {{cast from pointer to smaller type 'bool' loses information}}
+}
 
 namespace friend_as_a_forward_decl {