diff --git a/src/ia32/disasm-ia32.cc b/src/ia32/disasm-ia32.cc
index 44afdd6ddb..dc4c27e88a 100644
--- a/src/ia32/disasm-ia32.cc
+++ b/src/ia32/disasm-ia32.cc
@@ -924,14 +924,18 @@ int DisassemblerIA32::InstructionDecode(v8::internal::Vector<char> out_buffer,
         break;
 
       case 0xF6:
-        { int mod, regop, rm;
-          get_modrm(*(data+1), &mod, &regop, &rm);
-          if (mod == 3 && regop == eax) {
-            AppendToBuffer("test_b %s,%d", NameOfCPURegister(rm), *(data+2));
+        { data++;
+          int mod, regop, rm;
+          get_modrm(*data, &mod, &regop, &rm);
+          if (regop == eax) {
+            AppendToBuffer("test_b ");
+            data += PrintRightOperand(data);
+            int32_t imm = *data;
+            AppendToBuffer(",0x%x", imm);
+            data++;
           } else {
             UnimplementedInstruction();
           }
-          data += 3;
         }
         break;
 
diff --git a/test/cctest/test-disasm-ia32.cc b/test/cctest/test-disasm-ia32.cc
index f94cd457cd..c8e0197947 100644
--- a/test/cctest/test-disasm-ia32.cc
+++ b/test/cctest/test-disasm-ia32.cc
@@ -244,6 +244,9 @@ TEST(DisasmIa320) {
 
   __ test(edx, Immediate(12345));
   __ test(edx, Operand(ebx, ecx, times_8, 10000));
+  __ test(Operand(esi, edi, times_1, -20000000), Immediate(300000000));
+  __ test_b(edx, Operand(ecx, ebx, times_2, 1000));
+  __ test_b(Operand(eax, -20), 0x9A);
   __ nop();
 
   __ xor_(edx, 12345);