diff --git a/llvm/lib/CodeGen/MachineCopyPropagation.cpp b/llvm/lib/CodeGen/MachineCopyPropagation.cpp
--- a/llvm/lib/CodeGen/MachineCopyPropagation.cpp
+++ b/llvm/lib/CodeGen/MachineCopyPropagation.cpp
@@ -866,6 +866,8 @@
 
       if (!MO.getReg())
         continue;
+      if (MO.isDebug())
+        continue;
 
       if (MO.isDef())
         Tracker.invalidateRegister(MO.getReg().asMCReg(), *TRI);
diff --git a/llvm/test/CodeGen/X86/machine-copy-dbgvalue.mir b/llvm/test/CodeGen/X86/machine-copy-dbgvalue.mir
new file mode 100644
--- /dev/null
+++ b/llvm/test/CodeGen/X86/machine-copy-dbgvalue.mir
@@ -0,0 +1,18 @@
+# RUN: llc -mtriple=i686-- -run-pass machine-cp -verify-machineinstrs -o - %s | FileCheck %s
+
+
+---
+# Test that machine copy propagation ignores DBG_VALUE
+# CHECK-LABEL: name: foo
+# CHECK: bb.0:
+# CHECK-NEXT: $rax = MOV64ri 31
+# CHECK-NEXT: DBG_VALUE $rcx, $noreg
+# CHECK-NEXT: RETQ implicit killed $rax
+name: foo
+body: |
+  bb.0:
+    renamable $rcx = MOV64ri 31
+    DBG_VALUE $rcx, $noreg
+    $rax = COPY renamable killed $rcx
+    RETQ implicit killed $rax
+...