diff --git a/compiler/utils/x86/assembler_x86_test.cc b/compiler/utils/x86/assembler_x86_test.cc
index 5d34a51..305f3c4 100644
--- a/compiler/utils/x86/assembler_x86_test.cc
+++ b/compiler/utils/x86/assembler_x86_test.cc
@@ -114,6 +114,11 @@
       tertiary_register_names_.emplace(x86::Register(x86::EBX), "bl");
       tertiary_register_names_.emplace(x86::Register(x86::ECX), "cl");
       tertiary_register_names_.emplace(x86::Register(x86::EDX), "dl");
+      // FIXME: Refactor RepeatAw() to only use the tertiary for EAX, EBX, ECX, EDX
+      tertiary_register_names_.emplace(x86::Register(x86::EBP), "ch");
+      tertiary_register_names_.emplace(x86::Register(x86::ESP), "ah");
+      tertiary_register_names_.emplace(x86::Register(x86::ESI), "dh");
+      tertiary_register_names_.emplace(x86::Register(x86::EDI), "bh");
     }
 
     if (fp_registers_.size() == 0) {
@@ -322,6 +327,16 @@
   DriverStr(expected, "LoadLongConstant");
 }
 
+TEST_F(AssemblerX86Test, LockCmpxchgb) {
+  DriverStr(RepeatAw(&x86::X86Assembler::LockCmpxchgb,
+                     "lock cmpxchgb %{reg}, {mem}"), "lock_cmpxchgb");
+}
+
+TEST_F(AssemblerX86Test, LockCmpxchgw) {
+  DriverStr(RepeatAr(&x86::X86Assembler::LockCmpxchgw,
+                     "lock cmpxchgw %{reg}, {mem}"), "lock_cmpxchgw");
+}
+
 TEST_F(AssemblerX86Test, LockCmpxchgl) {
   DriverStr(RepeatAR(&x86::X86Assembler::LockCmpxchgl,
                      "lock cmpxchgl %{reg}, {mem}"), "lock_cmpxchgl");