diff --git a/bignum.cpp b/bignum.cpp
index 50312c9..f023798 100644
--- a/bignum.cpp
+++ b/bignum.cpp
@@ -25,9 +25,10 @@ extern "C" void bn_nbits_to_uchar(const uint32_t nBits, unsigned char *target)
 	hex2bin(target, buff, 32);
 }
 
+// unused, but should allow more than 256bits targets
+#if 0
 extern "C" double bn_hash_target_ratio(uint32_t* hash, uint32_t* target)
 {
-	unsigned char* uc;
 	double dhash;
 
 	if (!opt_showdiff)
@@ -47,6 +48,26 @@ extern "C" double bn_hash_target_ratio(uint32_t* hash, uint32_t* target)
 	else
 		return dhash;
 }
+#endif
+
+// compute the diff ratio between a found hash and the target
+extern "C" double bn_hash_target_ratio(uint32_t* hash, uint32_t* target)
+{
+	uint256 h, t;
+	double dhash;
+
+	if (!opt_showdiff)
+		return 0.0;
+
+	memcpy(&t, (void*) target, 32);
+	memcpy(&h, (void*) hash, 32);
+
+	dhash = h.getdouble();
+	if (dhash > 0.)
+		return t.getdouble() / dhash;
+	else
+		return dhash;
+}
 
 // store ratio in work struct
 extern "C" void bn_store_hash_target_ratio(uint32_t* hash, uint32_t* target, struct work* work)
@@ -56,4 +77,4 @@ extern "C" void bn_store_hash_target_ratio(uint32_t* hash, uint32_t* target, str
 		work->shareratio = bn_hash_target_ratio(hash, target);
 		work->sharediff = work->targetdiff * work->shareratio;
 	}
-}
+}
\ No newline at end of file
diff --git a/ccminer.cpp b/ccminer.cpp
index 0178a58..da55364 100644
--- a/ccminer.cpp
+++ b/ccminer.cpp
@@ -604,25 +604,24 @@ static bool jobj_binary(const json_t *obj, const char *key,
 static void calc_network_diff(struct work *work)
 {
 	// sample for diff 43.281 : 1c05ea29
-	uchar rtarget[48] = { 0 };
-	uint64_t *data64, d64;
 	// todo: endian reversed on longpoll could be zr5 specific...
 	uint32_t nbits = have_longpoll ? work->data[18] : swab32(work->data[18]);
-	uint32_t shift = (swab32(nbits) & 0xff); // 0x1c = 28
 	uint32_t bits = (nbits & 0xffffff);
-	int shfb = 8 * (26 - (shift - 3));
-
+	int16_t shift = (swab32(nbits) & 0xff); // 0x1c = 28
 #if 1
 	uint64_t diffone = 0x0000FFFF00000000ull;
 	double d = (double)0x0000ffff / (double)bits;
 	for (int m=shift; m < 29; m++) d *= 256.0;
 	for (int m=29; m < shift; m++) d /= 256.0;
 	if (opt_debug_diff)
-		applog(LOG_DEBUG, "diff: %f -> shift %u, bits %08x, shfb %d", d, shift, bits, shfb);
+		applog(LOG_DEBUG, "net diff: %f -> shift %u, bits %08x", d, shift, bits);
 	net_diff = d;
 	return;
 #else
+	uchar rtarget[48] = { 0 };
+	uint64_t *data64, d64;
 	uint64_t diffone = 0xFFFF000000000000ull; //swab64(0xFFFFull);
+	int shfb = 8 * (26 - (shift - 3));
 
 	switch (opt_algo) {
 		case ALGO_QUARK: