diff --git a/llvm/include/llvm/Transforms/IPO/PassManagerBuilder.h b/llvm/include/llvm/Transforms/IPO/PassManagerBuilder.h
index 70cb2476a9ea..c5d79165dfa2 100644
--- a/llvm/include/llvm/Transforms/IPO/PassManagerBuilder.h
+++ b/llvm/include/llvm/Transforms/IPO/PassManagerBuilder.h
@@ -142,7 +142,6 @@ public:
   const ModuleSummaryIndex *ImportSummary = nullptr;
 
   bool DisableTailCalls;
-  bool DisableUnitAtATime;
   bool DisableUnrollLoops;
   bool SLPVectorize;
   bool LoopVectorize;
diff --git a/llvm/tools/opt/opt.cpp b/llvm/tools/opt/opt.cpp
index b4c39e2fca8a..1a886ea7965d 100644
--- a/llvm/tools/opt/opt.cpp
+++ b/llvm/tools/opt/opt.cpp
@@ -172,11 +172,6 @@ CodeGenOptLevel("codegen-opt-level",
 static cl::opt<std::string>
 TargetTriple("mtriple", cl::desc("Override target triple for module"));
 
-static cl::opt<bool>
-UnitAtATime("funit-at-a-time",
-            cl::desc("Enable IPO. This corresponds to gcc's -funit-at-a-time"),
-            cl::init(true));
-
 static cl::opt<bool>
 DisableLoopUnrolling("disable-loop-unrolling",
                      cl::desc("Disable loop unrolling in all relevant passes"),
@@ -383,7 +378,6 @@ static void AddOptimizationPasses(legacy::PassManagerBase &MPM,
   } else {
     Builder.Inliner = createAlwaysInlinerLegacyPass();
   }
-  Builder.DisableUnitAtATime = !UnitAtATime;
   Builder.DisableUnrollLoops = (DisableLoopUnrolling.getNumOccurrences() > 0) ?
                                DisableLoopUnrolling : OptLevel == 0;