diff --git a/src/common/dwarf/dwarf2reader.cc b/src/common/dwarf/dwarf2reader.cc
index f2f3d58..a1e610d 100644
--- a/src/common/dwarf/dwarf2reader.cc
+++ b/src/common/dwarf/dwarf2reader.cc
@@ -870,12 +870,12 @@
  public:
   virtual ~Rule() { }
 
-  // Tell HANDLER that, at ADDRESS in the program, REGISTER can be
-  // recovered using this rule. If REGISTER is kCFARegister, then this rule
-  // describes how to compute the canonical frame address. Return what the
-  // HANDLER member function returned.
+  // Tell HANDLER that, at ADDRESS in the program, REG can be recovered using
+  // this rule. If REG is kCFARegister, then this rule describes how to compute
+  // the canonical frame address. Return what the HANDLER member function
+  // returned.
   virtual bool Handle(Handler *handler,
-                      uint64 address, int register) const = 0;
+                      uint64 address, int reg) const = 0;
 
   // Equality on rules. We use these to decide which rules we need
   // to report after a DW_CFA_restore_state instruction.