diff --git a/lib/Sema/Sema.cpp b/lib/Sema/Sema.cpp
index 8ce3ce0..b931cf8 100644
--- a/lib/Sema/Sema.cpp
+++ b/lib/Sema/Sema.cpp
@@ -18,6 +18,7 @@
 #include "clang/AST/DeclObjC.h"
 #include "clang/AST/Expr.h"
 #include "clang/Lex/Preprocessor.h"
+#include "clang/Basic/TargetInfo.h"
 using namespace clang;
 
 /// ConvertQualTypeToStringFn - This function is used to pretty print the 
@@ -109,15 +110,17 @@
   TUScope = S;
   PushDeclContext(S, Context.getTranslationUnitDecl());
   
-  // Install [u]int128_t.
-  PushOnScopeChains(TypedefDecl::Create(Context, CurContext,
-                                        SourceLocation(),
-                                        &Context.Idents.get("__int128_t"),
-                                        Context.Int128Ty), TUScope);
-  PushOnScopeChains(TypedefDecl::Create(Context, CurContext,
-                                        SourceLocation(),
-                                        &Context.Idents.get("__uint128_t"),
-                                        Context.UnsignedInt128Ty), TUScope);
+  if (PP.getTargetInfo().getPointerWidth(0) >= 64) {
+    // Install [u]int128_t for 64-bit targets.
+    PushOnScopeChains(TypedefDecl::Create(Context, CurContext,
+                                          SourceLocation(),
+                                          &Context.Idents.get("__int128_t"),
+                                          Context.Int128Ty), TUScope);
+    PushOnScopeChains(TypedefDecl::Create(Context, CurContext,
+                                          SourceLocation(),
+                                          &Context.Idents.get("__uint128_t"),
+                                          Context.UnsignedInt128Ty), TUScope);
+  }
   
   
   if (!PP.getLangOptions().ObjC1) return;
diff --git a/test/CodeGen/uint128_t.c b/test/CodeGen/uint128_t.c
index b3261dd..b3bf727 100644
--- a/test/CodeGen/uint128_t.c
+++ b/test/CodeGen/uint128_t.c
@@ -1,4 +1,4 @@
-// RUN: clang-cc %s -emit-llvm -o -
+// RUN: clang-cc %s -emit-llvm -o - -triple=x86_64-apple-darwin9
 
 typedef unsigned long long uint64_t;
 extern uint64_t numer;
diff --git a/test/CodeGenCXX/mangle.cpp b/test/CodeGenCXX/mangle.cpp
index 5540a68..c49abeb 100644
--- a/test/CodeGenCXX/mangle.cpp
+++ b/test/CodeGenCXX/mangle.cpp
@@ -1,4 +1,4 @@
-// RUN: clang-cc -emit-llvm %s -o %t &&
+// RUN: clang-cc -emit-llvm %s -o %t -triple=x86_64-apple-darwin9 && 
 
 // FIXME: This test is intentionally trivial, because we can't yet
 // CodeGen anything real in C++.
diff --git a/test/CodeGenObjC/encode-test-5.m b/test/CodeGenObjC/encode-test-5.m
index bf1a0a6..a76b071 100644
--- a/test/CodeGenObjC/encode-test-5.m
+++ b/test/CodeGenObjC/encode-test-5.m
@@ -1,4 +1,4 @@
-// RUN: clang-cc -triple=i686-apple-darwin9 -fnext-runtime -emit-llvm -o %t %s &&
+// RUN: clang-cc -triple=x86_64-apple-darwin9 -fnext-runtime -emit-llvm -o %t %s &&
 
 // RUN: grep ji %t | count 1 &&
 char *a = @encode(_Complex int);
diff --git a/test/Sema/types.c b/test/Sema/types.c
index d1e9fcc..3ee7675 100644
--- a/test/Sema/types.c
+++ b/test/Sema/types.c
@@ -1,4 +1,4 @@
-// RUN: clang-cc %s -pedantic -verify
+// RUN: clang-cc %s -pedantic -verify -triple=x86_64-apple-darwin9
 
 // rdar://6097662
 typedef int (*T)[2];