--- old/src/cpu/x86/vm/assembler_x86.hpp	2010-11-10 12:57:37.000000000 +0100
+++ new/src/cpu/x86/vm/assembler_x86.hpp	2010-11-10 12:57:37.000000000 +0100
@@ -22,6 +22,9 @@
  *
  */
 
+#ifndef CPU_X86_VM_ASSEMBLER_X86_HPP
+#define CPU_X86_VM_ASSEMBLER_X86_HPP
+
 class BiasedLockingCounters;
 
 // Contains all the definitions needed for x86 assembly code generation.
@@ -2272,3 +2275,5 @@
 #ifdef ASSERT
 inline bool AbstractAssembler::pd_check_instruction_mark() { return true; }
 #endif
+
+#endif // CPU_X86_VM_ASSEMBLER_X86_HPP