diff --git a/llvm/test/ThinLTO/X86/Inputs/cache.ll b/llvm/test/ThinLTO/X86/Inputs/cache.ll
new file mode 100644
index 000000000000..aab44cb80c76
--- /dev/null
+++ b/llvm/test/ThinLTO/X86/Inputs/cache.ll
@@ -0,0 +1,11 @@
+target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-apple-macosx10.11.0"
+
+
+define i32 @main() {
+entry:
+  call void (...) @globalfunc()
+  ret i32 0
+}
+
+declare void @globalfunc(...)
diff --git a/llvm/test/ThinLTO/X86/cache.ll b/llvm/test/ThinLTO/X86/cache.ll
new file mode 100644
index 000000000000..6254abe0a936
--- /dev/null
+++ b/llvm/test/ThinLTO/X86/cache.ll
@@ -0,0 +1,16 @@
+; RUN: opt -module-summary %s -o %t.bc
+; RUN: opt -module-summary %p/Inputs/funcimport.ll -o %t2.bc
+
+; Verify that enabling caching is working
+; RUN: rm -Rf %t.cache && mkdir %t.cache
+; RUN: llvm-lto -thinlto-action=run -exported-symbol=globalfunc %t2.bc  %t.bc -thinlto-cache-dir %t.cache
+; RUN: ls %t.cache/llvmcache.timestamp
+; RUN: ls %t.cache | count 3
+
+target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-apple-macosx10.11.0"
+
+define void @globalfunc() #0 {
+entry:
+  ret void
+}
diff --git a/llvm/tools/llvm-lto/llvm-lto.cpp b/llvm/tools/llvm-lto/llvm-lto.cpp
index 655e8c8379e6..51767977dd0f 100644
--- a/llvm/tools/llvm-lto/llvm-lto.cpp
+++ b/llvm/tools/llvm-lto/llvm-lto.cpp
@@ -109,6 +109,9 @@ static cl::opt<std::string> ThinLTOModuleId(
     cl::desc("For the module ID for the file to process, useful to "
              "match what is in the index."));
 
+static cl::opt<std::string>
+    ThinLTOCacheDir("thinlto-cache-dir", cl::desc("Enable ThinLTO caching."));
+
 static cl::opt<bool>
     SaveModuleFile("save-merged-module", cl::init(false),
                    cl::desc("Write merged LTO module to file before CodeGen"));
@@ -350,6 +353,7 @@ public:
   ThinLTOProcessing(const TargetOptions &Options) {
     ThinGenerator.setCodePICModel(RelocModel);
     ThinGenerator.setTargetOptions(Options);
+    ThinGenerator.setCacheDir(ThinLTOCacheDir);
 
     // Add all the exported symbols to the table of symbols to preserve.
     for (unsigned i = 0; i < ExportedSymbols.size(); ++i)