diff --git a/compiler/utils/x86/assembler_x86.h b/compiler/utils/x86/assembler_x86.h
index 511eeb9..2964dba 100644
--- a/compiler/utils/x86/assembler_x86.h
+++ b/compiler/utils/x86/assembler_x86.h
@@ -235,6 +235,7 @@
   }
 };
 
+std::ostream& operator<<(std::ostream& os, const Address& addr);
 
 // This is equivalent to the Label class, used in a slightly different context. We
 // inherit the functionality of the Label class, but prevent unintended