diff --git a/lib/CodeGen/MachineBasicBlock.cpp b/lib/CodeGen/MachineBasicBlock.cpp
index 71e6b3e..82ff769 100644
--- a/lib/CodeGen/MachineBasicBlock.cpp
+++ b/lib/CodeGen/MachineBasicBlock.cpp
@@ -148,7 +148,8 @@
     os << " %reg" << RegNo;
 }
 
-void MachineBasicBlock::print(std::ostream &OS) const {
+void MachineBasicBlock::print(std::ostream &OS,
+                              const PrefixPrinter &prefix) const {
   const MachineFunction *MF = getParent();
   if(!MF) {
     OS << "Can't print out MachineBasicBlock because parent MachineFunction"
@@ -181,6 +182,7 @@
   }
   
   for (const_iterator I = begin(); I != end(); ++I) {
+    OS << prefix(*I);
     OS << "\t";
     I->print(OS, &getParent()->getTarget());
   }