Index: tools/llvm-objdump/llvm-objdump.cpp
===================================================================
--- tools/llvm-objdump/llvm-objdump.cpp
+++ tools/llvm-objdump/llvm-objdump.cpp
@@ -405,6 +405,11 @@
                  raw_ostream &OS,
                  StringRef Annot,
                  MCSubtargetInfo const &STI) override {
+    if (!MI) {
+      OS << " <unknown>";
+      return;
+    }
+
     SmallString<40> InstStr;
     raw_svector_ostream IS(InstStr);