diff --git a/llvm/lib/Transforms/Utils/LoopVersioning.cpp b/llvm/lib/Transforms/Utils/LoopVersioning.cpp
index 5b1fa8eec2f5..83af2d8ea33b 100644
--- a/llvm/lib/Transforms/Utils/LoopVersioning.cpp
+++ b/llvm/lib/Transforms/Utils/LoopVersioning.cpp
@@ -125,12 +125,12 @@ void LoopVersioning::addPHINodes(
     const SmallVectorImpl<Instruction *> &DefsUsedOutside) {
   BasicBlock *PHIBlock = VersionedLoop->getExitBlock();
   assert(PHIBlock && "No single successor to loop exit block");
+  PHINode *PN;
 
+  // First add a single-operand PHI for each DefsUsedOutside if one does not
+  // exists yet.
   for (auto *Inst : DefsUsedOutside) {
-    auto *NonVersionedLoopInst = cast<Instruction>(VMap[Inst]);
-    PHINode *PN;
-
-    // First see if we have a single-operand PHI with the value defined by the
+    // See if we have a single-operand PHI with the value defined by the
     // original loop.
     for (auto I = PHIBlock->begin(); (PN = dyn_cast<PHINode>(I)); ++I) {
       if (PN->getIncomingValue(0) == Inst) {
@@ -148,8 +148,20 @@ void LoopVersioning::addPHINodes(
           User->replaceUsesOfWith(Inst, PN);
       PN->addIncoming(Inst, VersionedLoop->getExitingBlock());
     }
-    // Add the new incoming value from the non-versioned loop.
-    PN->addIncoming(NonVersionedLoopInst, NonVersionedLoop->getExitingBlock());
+  }
+
+  // Then for each PHI add the operand for the edge from the cloned loop.
+  for (auto I = PHIBlock->begin(); (PN = dyn_cast<PHINode>(I)); ++I) {
+    assert(PN->getNumOperands() == 1 &&
+           "Exit block should only have on predecessor");
+
+    // If the definition was cloned used that otherwise use the same value.
+    Value *ClonedValue = PN->getIncomingValue(0);
+    auto Mapped = VMap.find(ClonedValue);
+    if (Mapped != VMap.end())
+      ClonedValue = Mapped->second;
+
+    PN->addIncoming(ClonedValue, NonVersionedLoop->getExitingBlock());
   }
 }
 
diff --git a/llvm/test/Transforms/LoopVersioning/incorrect-phi.ll b/llvm/test/Transforms/LoopVersioning/incorrect-phi.ll
new file mode 100644
index 000000000000..fcecdb349003
--- /dev/null
+++ b/llvm/test/Transforms/LoopVersioning/incorrect-phi.ll
@@ -0,0 +1,62 @@
+; RUN: opt -loop-versioning -S < %s | FileCheck %s
+
+; Make sure all PHIs are properly updated in the exit block.  Based on
+; PR28037.
+
+target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+@x = external global [2 x [3 x [5 x i16]]]
+
+; CHECK-LABEL: @phi_with_undef
+define void @phi_with_undef() {
+bb6.lr.ph:                                        ; preds = %bb5.preheader
+  br label %bb6
+
+bb6:                                              ; preds = %bb6.lr.ph, %bb6
+  %_tmp1423 = phi i16 [ undef, %bb6.lr.ph ], [ %_tmp142, %bb6 ]
+  %_tmp123 = getelementptr [2 x [3 x [5 x i16]]], [2 x [3 x [5 x i16]]]* @x, i16 0, i64 undef
+  %_tmp125 = sext i16 %_tmp1423 to i64
+  %_tmp126 = getelementptr [3 x [5 x i16]], [3 x [5 x i16]]* %_tmp123, i16 0, i64 %_tmp125
+  %_tmp129 = getelementptr [5 x i16], [5 x i16]* %_tmp126, i16 0, i64 undef
+  %_tmp130 = load i16, i16* %_tmp129
+  store i16 undef, i16* getelementptr ([2 x [3 x [5 x i16]]], [2 x [3 x [5 x i16]]]* @x, i64 0, i64 undef, i64 undef, i64 undef)
+  %_tmp142 = add i16 %_tmp1423, 1
+  br i1 false, label %bb6, label %loop.exit
+
+loop.exit:                                ; preds = %bb6
+  %_tmp142.lcssa = phi i16 [ %_tmp142, %bb6 ]
+  %split = phi i16 [ undef, %bb6 ]
+; CHECK: %split = phi i16 [ undef, %bb6 ], [ undef, %bb6.lver.orig ]
+  br label %bb9
+
+bb9:                                              ; preds = %bb9.loopexit, %bb1
+  ret void
+}
+
+; CHECK-LABEL: @phi_with_non_loop_defined_value
+define void @phi_with_non_loop_defined_value() {
+bb6.lr.ph:                                        ; preds = %bb5.preheader
+  %t = add i16 1, 1
+  br label %bb6
+
+bb6:                                              ; preds = %bb6.lr.ph, %bb6
+  %_tmp1423 = phi i16 [ undef, %bb6.lr.ph ], [ %_tmp142, %bb6 ]
+  %_tmp123 = getelementptr [2 x [3 x [5 x i16]]], [2 x [3 x [5 x i16]]]* @x, i16 0, i64 undef
+  %_tmp125 = sext i16 %_tmp1423 to i64
+  %_tmp126 = getelementptr [3 x [5 x i16]], [3 x [5 x i16]]* %_tmp123, i16 0, i64 %_tmp125
+  %_tmp129 = getelementptr [5 x i16], [5 x i16]* %_tmp126, i16 0, i64 undef
+  %_tmp130 = load i16, i16* %_tmp129
+  store i16 undef, i16* getelementptr ([2 x [3 x [5 x i16]]], [2 x [3 x [5 x i16]]]* @x, i64 0, i64 undef, i64 undef, i64 undef)
+  %_tmp142 = add i16 %_tmp1423, 1
+  br i1 false, label %bb6, label %loop.exit
+
+loop.exit:                                ; preds = %bb6
+  %_tmp142.lcssa = phi i16 [ %_tmp142, %bb6 ]
+  %split = phi i16 [ %t, %bb6 ]
+; CHECK: %split = phi i16 [ %t, %bb6 ], [ %t, %bb6.lver.orig ]
+  br label %bb9
+
+bb9:                                              ; preds = %bb9.loopexit, %bb1
+  ret void
+}