diff --git a/main.c b/main.c
index c01b20d..cf46562 100644
--- a/main.c
+++ b/main.c
@@ -91,6 +91,55 @@ static void filters_init()
 #endif
 }
 
+#ifdef INTFILTER
+// o - old filter, n - new
+// return -1 - old stays, 0 - no conflict, 1 - new overrides old
+// assumes masked bits are cleared already
+static inline int ifilter_conflict(struct intfilter *o,struct intfilter *n)
+{
+	if ((o->f & n->m) != (n->f & o->m))
+		return 0;
+	// determine which filter contain less bits
+	// this shit needs code independent of endianess, so not direct <=
+	if (memcmp(&o->m,&n->m,sizeof(o->m)) <= 0)
+		return -1;
+	return 1;
+}
+#else
+// o - old filter, n - new
+// return: -1 - old stays, 0 - no conflict, 1 - new overrides old
+// assumes irrelevant bits are cleared already
+static inline int bfilter_conflict(struct binfilter *o,struct binfilter *n)
+{
+	for (size_t i = 0;i < sizeof(o->f);++i) {
+		u8 oo,nn;
+		if (i < n->len)
+			oo = o->f[i];
+		else if (i == n->len)
+			oo = o->f[i] & n->mask;
+		else
+			oo = 0;
+		if (i < o->len)
+			nn = n->f[i];
+		else if (i == o->len)
+			nn = n->f[i] & o->mask;
+		else
+			nn = 0;
+		if (oo != nn)
+			return 0;
+	}
+	// functional filters subset was the same
+	// determine which filter contain less bits
+	if (o->len < n->len)
+		return -1;
+	if (o->len > n->len)
+		return 1;
+	if (o->mask <= n->mask)
+		return -1;
+	return 1;
+}
+#endif
+
 static void filters_add(const char *filter)
 {
 	struct binfilter bf;
@@ -102,6 +151,8 @@ static void filters_add(const char *filter)
 	} fc,mc;
 #endif
 
+	memset(&bf,0,sizeof(bf));
+
 	if (!base32_valid(filter,&ret)) {
 		fprintf(stderr, "filter \"%s\" is invalid\n", filter);
 		return;
@@ -120,7 +171,6 @@ static void filters_add(const char *filter)
 	}
 	ret2 = base32_from(bf.f,&bf.mask,filter);
 	assert(ret == ret2);
-	//printf("--m:%02X\n", bf.mask);
 	bf.len = ret - 1;
 #ifdef INTFILTER
 	mc.i = 0;
@@ -129,9 +179,29 @@ static void filters_add(const char *filter)
 	mc.b[bf.len] = bf.mask;
 	memcpy(fc.b,bf.f,8);
 	fc.i &= mc.i;
-	struct intfilter ifltr = {fc.i,mc.i};
+	struct intfilter ifltr = {.f = fc.i,.m = mc.i};
+	VEC_FOR(ifilters,i) {
+		int c = ifilter_conflict(&VEC_BUF(ifilters,i),&ifltr);
+		if (c < 0)
+			return; // old filter eats us
+		else if (c > 0) {
+			VEC_REMOVE(ifilters,i);
+			--i;
+			// we eat old filter
+		}
+	}
 	VEC_ADD(ifilters,ifltr);
 #else
+	VEC_FOR(bfilters,i) {
+		int c = bfilter_conflict(&VEC_BUF(bfilters,i),&bf);
+		if (c < 0)
+			return; // old filter eats us
+		else if (c > 0) {
+			VEC_REMOVE(bfilters,i);
+			--i;
+			// we eat old filter
+		}
+	}
 	VEC_ADD(bfilters,bf);
 #endif
 }
@@ -721,14 +791,14 @@ int main(int argc,char **argv)
 	signal(SIGINT,termhandler);
 
 	VEC_INIT(threads);
-	VEC_ADDN(threads,pthread_t,numthreads);
+	VEC_ADDN(threads,numthreads);
 #ifdef STATISTICS
 	VEC_INIT(stats);
+	VEC_ADDN(stats,numthreads);
+	VEC_ZERO(stats);
 	VEC_INIT(tstats);
-	VEC_ADDN(stats,struct statstruct,numthreads);
-	VEC_ADDN(tstats,struct tstatstruct,numthreads);
-	memset(&VEC_BUF(stats,0),0,sizeof(struct statstruct) * VEC_LENGTH(stats));
-	memset(&VEC_BUF(tstats,0),0,sizeof(struct tstatstruct) * VEC_LENGTH(tstats));
+	VEC_ADDN(tstats,numthreads);
+	VEC_ZERO(tstats);
 #endif
 
 	for (size_t i = 0;i < VEC_LENGTH(threads);++i) {
diff --git a/vec.h b/vec.h
index f7d0631..64477e7 100644
--- a/vec.h
+++ b/vec.h
@@ -1,38 +1,74 @@
-#define VEC_STRUCT(typename, inttype) \
+#define VEC_STRUCT(typename,inttype) \
 struct typename { \
 	inttype *buf; \
 	size_t len, alen; \
 }
 
-#define VEC_INIT(ctl) memset(&ctl, 0, sizeof(ctl))
+#define VEC_INIT(ctl) memset(&ctl,0,sizeof(ctl))
 
-#define VEC_ADD(ctl, val) { \
+#define VEC_ADD1(ctl) { \
 	if (!(ctl).alen) { \
 		(ctl).alen = 8; \
-		(ctl).buf = malloc(8 * sizeof(val)); \
+		(ctl).buf = malloc(8 * sizeof(*(ctl).buf)); \
 	} else if ((ctl).len >= (ctl).alen) { \
 		(ctl).alen *= 2; \
-		(ctl).buf = realloc((ctl).buf, (ctl).alen * sizeof(val)); \
+		(ctl).buf = realloc((ctl).buf,(ctl).alen * sizeof(*(ctl).buf)); \
 	} \
-	(ctl).buf[(ctl).len++] = val; \
+	++(ctl).len; \
 }
 
-#define VEC_ADDN(ctl, valt, n) { \
+#define VEC_ADD(ctl,val) { \
 	if (!(ctl).alen) { \
 		(ctl).alen = 8; \
-		(ctl).buf = malloc(8 * sizeof(valt)); \
+		(ctl).buf = malloc(8 * sizeof(*(ctl).buf)); \
+	} else if ((ctl).len >= (ctl).alen) { \
+		(ctl).alen *= 2; \
+		(ctl).buf = realloc((ctl).buf,(ctl).alen * sizeof(*(ctl).buf)); \
+	} \
+	(ctl).buf[(ctl).len++] = (val); \
+}
+
+#define VEC_ADDN(ctl,n) { \
+	if (!(ctl).alen) { \
+		(ctl).alen = 8; \
+		(ctl).buf = malloc(8 * sizeof(*(ctl).buf)); \
 	} \
 	size_t nlen = (ctl).alen; \
 	while ((ctl).len + n > nlen) \
 		nlen *= 2; \
 	if (nlen > (ctl).alen) { \
 		(ctl).alen = nlen; \
-		(ctl).buf = realloc((ctl).buf, nlen * sizeof(valt)); \
+		(ctl).buf = realloc((ctl).buf,nlen * sizeof(*(ctl).buf)); \
 	} \
 	(ctl).len += n; \
 }
 
-#define VEC_FREE(ctl) { free((ctl).buf); memset(&(ctl), 0, sizeof((ctl))); }
+#define VEC_REMOVE(ctl,n) { \
+	--(ctl).len; \
+	memmove( \
+		&(ctl).buf[(n) * sizeof(*(ctl).buf)], \
+		&(ctl).buf[(n + 1) * sizeof(*(ctl).buf)], \
+		((ctl).len - (n)) * sizeof(*(ctl).buf)); \
+}
+
+#define VEC_INSERT(ctl,n,val) { \
+	VEC_ADD1(ctl); \
+	memmove( \
+		&(ctl).buf[(n + 1) * sizeof(*(ctl).buf)], \
+		&(ctl).buf[(n) * sizeof(*(ctl).buf)], \
+		((ctl).len - (n) - 1) * sizeof(*(ctl).buf)); \
+	(ctl).buf[n] = (val); \
+}
+
+#define VEC_ZERO(ctl) \
+	memset((ctl).buf,0,(ctl).len * sizeof(*(ctl).buf))
+
+#define VEC_FREE(ctl) { \
+	free((ctl).buf); \
+	memset(&(ctl), 0, sizeof((ctl))); \
+}
 
 #define VEC_LENGTH(ctl) ((ctl).len)
-#define VEC_BUF(ctl, num) ((ctl).buf[num])
+#define VEC_BUF(ctl,num) ((ctl).buf[num])
+
+#define VEC_FOR(ctl,it) for (size_t it = 0;it < VEC_LENGTH((ctl));++it)