diff --git a/include/uc_priv.h b/include/uc_priv.h
index 22f494e..1aa7b3a 100644
--- a/include/uc_priv.h
+++ b/include/uc_priv.h
@@ -245,6 +245,12 @@ struct uc_struct {
     uint32_t target_page_align;
     uint64_t next_pc;   // save next PC for some special cases
     bool hook_insert;	// insert new hook at begin of the hook list (append by default)
+    
+#ifdef UNICORN_AFL
+    unsigned char *afl_area_ptr;
+    int afl_compcov_level;
+    unsigned int afl_inst_rms;
+#endif
 };
 
 // Metadata stub for the variable-size cpu context used with uc_context_*()
diff --git a/qemu/target-i386/translate.c b/qemu/target-i386/translate.c
index 36fae09..196d346 100644
--- a/qemu/target-i386/translate.c
+++ b/qemu/target-i386/translate.c
@@ -33,6 +33,12 @@
 
 #include "uc_priv.h"
 
+#if defined(UNICORN_AFL)
+#include "../../afl-unicorn-cpu-translate-inl.h"
+#else
+#define afl_gen_compcov(a,b,c,d,e,f) do {} while (0)
+#endif
+
 #define PREFIX_REPZ   0x01
 #define PREFIX_REPNZ  0x02
 #define PREFIX_LOCK   0x04
@@ -1555,6 +1561,7 @@ static void gen_op(DisasContext *s, int op, TCGMemOp ot, int d)
     case OP_SUBL:
         tcg_gen_mov_tl(tcg_ctx, cpu_cc_srcT, *cpu_T[0]);
         tcg_gen_sub_tl(tcg_ctx, *cpu_T[0], *cpu_T[0], *cpu_T[1]);
+        afl_gen_compcov(tcg_ctx, s->pc, *cpu_T[0], *cpu_T[1], ot, d == OR_EAX);
         gen_op_st_rm_T0_A0(s, ot, d);
         gen_op_update2_cc(tcg_ctx);
         set_cc_op(s, CC_OP_SUBB + ot);
@@ -1582,6 +1589,7 @@ static void gen_op(DisasContext *s, int op, TCGMemOp ot, int d)
         tcg_gen_mov_tl(tcg_ctx, cpu_cc_src, *cpu_T[1]);
         tcg_gen_mov_tl(tcg_ctx, cpu_cc_srcT, *cpu_T[0]);
         tcg_gen_sub_tl(tcg_ctx, cpu_cc_dst, *cpu_T[0], *cpu_T[1]);
+        afl_gen_compcov(tcg_ctx, s->pc, *cpu_T[0], *cpu_T[1], ot, d == OR_EAX);
         set_cc_op(s, CC_OP_SUBB + ot);
         break;
     }
diff --git a/qemu/tcg-runtime.c b/qemu/tcg-runtime.c
index 21b022a..14d7891 100644
--- a/qemu/tcg-runtime.c
+++ b/qemu/tcg-runtime.c
@@ -31,9 +31,14 @@
 
 #define DEF_HELPER_FLAGS_2(name, flags, ret, t1, t2) \
   dh_ctype(ret) HELPER(name) (dh_ctype(t1), dh_ctype(t2));
+#define DEF_HELPER_FLAGS_4(name, flags, ret, t1, t2, t3, t4) \
+  dh_ctype(ret) HELPER(name) (dh_ctype(t1), dh_ctype(t2), dh_ctype(t3), dh_ctype(t4));
 
 #include "tcg-runtime.h"
 
+#ifdef UNICORN_AFL
+#include "../afl-unicorn-tcg-runtime-inl.h"
+#endif
 
 /* 32-bit helpers */
 
diff --git a/qemu/tcg/tcg-op.h b/qemu/tcg/tcg-op.h
index 38b7dd9..c5a9af9 100644
--- a/qemu/tcg/tcg-op.h
+++ b/qemu/tcg/tcg-op.h
@@ -27,6 +27,10 @@
 
 int gen_new_label(TCGContext *);
 
+#ifdef UNICORN_AFL
+#include "../../afl-unicorn-tcg-op-inl.h"
+#endif
+
 static inline void gen_uc_tracecode(TCGContext *tcg_ctx, int32_t size, int32_t type, void *uc, uint64_t pc)
 {
     TCGv_i32 tsize = tcg_const_i32(tcg_ctx, size);
diff --git a/qemu/tcg/tcg-runtime.h b/qemu/tcg/tcg-runtime.h
index 23a0c37..90b993c 100644
--- a/qemu/tcg/tcg-runtime.h
+++ b/qemu/tcg/tcg-runtime.h
@@ -14,3 +14,9 @@ DEF_HELPER_FLAGS_2(sar_i64, TCG_CALL_NO_RWG_SE, s64, s64, s64)
 
 DEF_HELPER_FLAGS_2(mulsh_i64, TCG_CALL_NO_RWG_SE, s64, s64, s64)
 DEF_HELPER_FLAGS_2(muluh_i64, TCG_CALL_NO_RWG_SE, i64, i64, i64)
+
+#ifdef UNICORN_AFL
+DEF_HELPER_FLAGS_4(afl_compcov_log_16, 0, void, ptr, i64, i64, i64)
+DEF_HELPER_FLAGS_4(afl_compcov_log_32, 0, void, ptr, i64, i64, i64)
+DEF_HELPER_FLAGS_4(afl_compcov_log_64, 0, void, ptr, i64, i64, i64)
+#endif
diff --git a/qemu/unicorn_common.h b/qemu/unicorn_common.h
index 8dcbb3e..11e18b4 100644
--- a/qemu/unicorn_common.h
+++ b/qemu/unicorn_common.h
@@ -84,6 +84,10 @@ static inline void uc_common_init(struct uc_struct* uc)
 
     if (!uc->release)
         uc->release = release_common;
+
+#ifdef UNICORN_AFL
+    uc->afl_area_ptr = 0;
+#endif
 }
 
 #endif