diff --git a/tests/asmtest.S b/tests/asmtest.S
index bf51c44..7f2e4ca 100644
--- a/tests/asmtest.S
+++ b/tests/asmtest.S
@@ -613,6 +613,7 @@ int $0x10
     lfence
     mfence
     sfence
+    clflush 0x1000(%rax,%rcx)
 #endif
 
     emms
diff --git a/x86_64-asm.h b/x86_64-asm.h
index a40b697..c590c57 100644
--- a/x86_64-asm.h
+++ b/x86_64-asm.h
@@ -488,6 +488,7 @@ ALT(DEF_ASM_OP2(movhps, 0x0f17, 0, OPC_MODRM, OPT_SSE, OPT_EA | OPT_REG32 ))
     DEF_ASM_OP0L(lfence, 0x0fae, 5, OPC_MODRM)
     DEF_ASM_OP0L(mfence, 0x0fae, 6, OPC_MODRM)
     DEF_ASM_OP0L(sfence, 0x0fae, 7, OPC_MODRM)
+    DEF_ASM_OP1(clflush, 0x0fae, 7, OPC_MODRM, OPT_EA)
 #undef ALT
 #undef DEF_ASM_OP0
 #undef DEF_ASM_OP0L