diff --git a/lib/CodeGen/LiveIntervalAnalysis.cpp b/lib/CodeGen/LiveIntervalAnalysis.cpp
index 9b01356a24e..3d22f709a45 100644
--- a/lib/CodeGen/LiveIntervalAnalysis.cpp
+++ b/lib/CodeGen/LiveIntervalAnalysis.cpp
@@ -939,10 +939,13 @@ public:
         hasRegMask = true;
       if (!MO.isReg())
         continue;
-      // Aggressively clear all kill flags.
-      // They are reinserted by VirtRegRewriter.
-      if (MO.isUse())
+      if (MO.isUse()) {
+        if (!MO.readsReg())
+          continue;
+        // Aggressively clear all kill flags.
+        // They are reinserted by VirtRegRewriter.
         MO.setIsKill(false);
+      }
 
       unsigned Reg = MO.getReg();
       if (!Reg)
diff --git a/unittests/MI/LiveIntervalTest.cpp b/unittests/MI/LiveIntervalTest.cpp
index 104bd7fe7fb..afd3b51793b 100644
--- a/unittests/MI/LiveIntervalTest.cpp
+++ b/unittests/MI/LiveIntervalTest.cpp
@@ -300,6 +300,17 @@ TEST(LiveIntervalTest, MoveDownKillFollowing) {
   });
 }
 
+TEST(LiveIntervalTest, MoveUndefUse) {
+  liveIntervalTest(
+"    %0 = IMPLICIT_DEF\n"
+"    NOOP implicit undef %0\n"
+"    NOOP implicit %0\n"
+"    NOOP\n",
+  [](MachineFunction &MF, LiveIntervals &LIS) {
+    testHandleMove(MF, LIS, 1, 3);
+  });
+}
+
 int main(int argc, char **argv) {
   ::testing::InitGoogleTest(&argc, argv);
   initLLVM();