diff --git a/daemon/call_interfaces.c b/daemon/call_interfaces.c
index 58fc65bb6..ed8217054 100644
--- a/daemon/call_interfaces.c
+++ b/daemon/call_interfaces.c
@@ -615,7 +615,7 @@ INLINE void ng_osrtp_option(sdp_ng_flags *out, str *s, helper_arg dummy) {
 static void call_ng_flags_str_pair_ht(sdp_ng_flags *out, str *s, helper_arg arg) {
 	str *s_copy = str_dup_escape(s);
 	str token;
-	if (str_token(&token, s_copy, '>')) {
+	if (!str_token(&token, s_copy, '>')) {
 		ilog(LOG_WARN, "SDP manipulations: Ignoring invalid token '" STR_FORMAT "'", STR_FMT(s));
 		free(s_copy);
 		return;
@@ -799,7 +799,7 @@ static void call_ng_flags_list(sdp_ng_flags *out, bencode_item_t *list,
 	if (list->type != BENCODE_LIST) {
 		if (bencode_get_str(list, &s)) {
 			str token;
-			while (str_token_sep(&token, &s, ',') == 0)
+			while (str_token_sep(&token, &s, ','))
 				str_callback(out, &token, arg);
 		}
 		else
@@ -923,7 +923,7 @@ static void call_ng_flags_str_q_multi(sdp_ng_flags *out, str *s, helper_arg arg)
 	if (s_copy->len == 0)
 		ilog(LOG_DEBUG, "Hm, nothing to parse.");
 
-	while (str_token_sep(&token, s_copy, ';') == 0)
+	while (str_token_sep(&token, s_copy, ';'))
 	{
 		str * ret = str_dup(&token);
 		t_queue_push_tail(q, ret);
@@ -968,7 +968,7 @@ static const struct sdp_attr_helper sdp_attr_helper_substitute = {
 static void call_ng_flags_sdp_attr_helper(sdp_ng_flags *out, str *s, helper_arg arg) {
 	// get media type
 	str token;
-	if (str_token(&token, s, '-'))
+	if (!str_token(&token, s, '-'))
 		return;
 	struct sdp_manipulations *sm = sdp_manipulations_get_by_name(out, &token);
 	if (!sm) {
@@ -1428,7 +1428,7 @@ static void call_ng_flags_freqs(sdp_ng_flags *out, bencode_item_t *value) {
 		case BENCODE_STRING:;
 			str s, token;
 			bencode_get_str(value, &s);
-			while (str_token_sep(&token, &s, ',') == 0) {
+			while (str_token_sep(&token, &s, ',')) {
 				val = str_to_i(&token, 0);
 				g_array_append_val(out->frequencies, val);
 			}
diff --git a/daemon/cli.c b/daemon/cli.c
index 90bc3f20e..d9ec71fee 100644
--- a/daemon/cli.c
+++ b/daemon/cli.c
@@ -1148,7 +1148,7 @@ static void cli_incoming_debug(str *instr, struct cli_writer *cw) {
 	}
 
 	str callid;
-	if (str_token_sep(&callid, instr, ' '))
+	if (!str_token_sep(&callid, instr, ' '))
 		callid = STR_NULL;
 
 	if (!callid.len) {
@@ -1285,7 +1285,7 @@ static void cli_incoming_set_loglevel(str *instr, struct cli_writer *cw) {
 
 	str subsys = STR_NULL;
 	if (instr->len && (instr->s[0] < '0' || instr->s[0] > '9'))
-		if (str_token_sep(&subsys, instr, ' '))
+		if (!str_token_sep(&subsys, instr, ' '))
 			subsys = STR_NULL;
 
 	if (!instr->len) {
@@ -1440,7 +1440,7 @@ static void cli_incoming_call(str *instr, struct cli_writer *cw) {
 	}
 
 	str callid;
-	if (str_token_sep(&callid, instr, ' '))
+	if (!str_token_sep(&callid, instr, ' '))
 		callid = STR_NULL;
 
 	if (!callid.len) {
@@ -1502,7 +1502,7 @@ static void cli_incoming_call_tag(str *instr, struct cli_writer *cw) {
 	}
 
 	str tag;
-	if (str_token_sep(&tag, instr, ' '))
+	if (!str_token_sep(&tag, instr, ' '))
 		tag = STR_NULL;
 
 	if (!tag.len) {
diff --git a/daemon/codec.c b/daemon/codec.c
index 21629e91c..e9d1f1c5c 100644
--- a/daemon/codec.c
+++ b/daemon/codec.c
@@ -2460,7 +2460,7 @@ rtp_payload_type *codec_make_payload_type(const str *codec_str, enum media_type
 
 	str codec_fmt = *codec_str;
 	str codec, parms, chans, opts, extra_opts, fmt_params, codec_opts;
-	if (str_token_sep(&codec, &codec_fmt, '/'))
+	if (!str_token_sep(&codec, &codec_fmt, '/'))
 		return NULL;
 	str_token_sep(&parms, &codec_fmt, '/');
 	str_token_sep(&chans, &codec_fmt, '/');
diff --git a/daemon/janus.c b/daemon/janus.c
index f3e1c7ca2..76230b5a8 100644
--- a/daemon/janus.c
+++ b/daemon/janus.c
@@ -1944,14 +1944,14 @@ const char *websocket_janus_post(struct websocket_message *wm) {
 
 	// parse out session ID and handle ID if given
 	str s;
-	if (str_token_sep(&s, &uri, '/'))
+	if (!str_token_sep(&s, &uri, '/'))
 		goto done;
 	if (str_cmp(&s, "janus"))
 		goto done;
-	if (str_token_sep(&s, &uri, '/'))
+	if (!str_token_sep(&s, &uri, '/'))
 		goto done;
 	session_id = str_to_ui(&s, 0);
-	if (str_token_sep(&s, &uri, '/'))
+	if (!str_token_sep(&s, &uri, '/'))
 		goto done;
 	handle_id = str_to_ui(&s, 0);
 
diff --git a/daemon/redis.c b/daemon/redis.c
index 9a1bfa6a5..d6fa503d6 100644
--- a/daemon/redis.c
+++ b/daemon/redis.c
@@ -1530,7 +1530,7 @@ static rtp_payload_type *rbl_cb_plts_g(str *s, struct redis_list *list, void *pt
 	str ptype;
 	struct call_media *med = ptr;
 
-	if (str_token(&ptype, s, '/'))
+	if (!str_token(&ptype, s, '/'))
 		return NULL;
 
 	rtp_payload_type *pt = codec_make_payload_type(s, med->type_id);
@@ -1667,7 +1667,7 @@ static int redis_link_sfds(struct redis_list *sfds, struct redis_list *streams)
 static int rbl_subs_cb(str *s, callback_arg_t dummy, struct redis_list *list, void *ptr) {
 	str token;
 
-	if (str_token_sep(&token, s, '/'))
+	if (!str_token_sep(&token, s, '/'))
 		return -1;
 
 	unsigned int media_unique_id = str_to_i(&token, 0);
@@ -1676,11 +1676,11 @@ static int rbl_subs_cb(str *s, callback_arg_t dummy, struct redis_list *list, vo
 	bool rtcp_only = false;
 	bool egress = false;
 
-	if (!str_token_sep(&token, s, '/')) {
+	if (str_token_sep(&token, s, '/')) {
 		offer_answer = str_to_i(&token, 0) ? true : false;
-		if (!str_token_sep(&token, s, '/')) {
+		if (str_token_sep(&token, s, '/')) {
 			rtcp_only = str_to_i(&token, 0) ? true : false;
-			if (!str_token_sep(&token, s, '/'))
+			if (str_token_sep(&token, s, '/'))
 				egress = str_to_i(&token, 0) ? true : false;
 		}
 	}
diff --git a/daemon/sdp.c b/daemon/sdp.c
index 09f2f2ce2..aa247d4eb 100644
--- a/daemon/sdp.c
+++ b/daemon/sdp.c
@@ -480,7 +480,7 @@ static int parse_address(struct network_address *address) {
 			&address->address_type, &address->address);
 }
 
-#define EXTRACT_TOKEN(field) do { if (str_token_sep(&output->field, value_str, ' ')) return -1; } while (0)
+#define EXTRACT_TOKEN(field) do { if (!str_token_sep(&output->field, value_str, ' ')) return -1; } while (0)
 #define EXTRACT_NETWORK_ADDRESS_NP(field)			\
 		do { EXTRACT_TOKEN(field.network_type);		\
 		EXTRACT_TOKEN(field.address_type);		\
@@ -552,7 +552,7 @@ static int parse_media(str *value_str, struct sdp_media *output) {
 	/* to split the "formats" list into tokens, we abuse some vars */
 	str formats = output->formats;
 	str format;
-	while (!str_token_sep(&format, &formats, ' ')) {
+	while (str_token_sep(&format, &formats, ' ')) {
 		sp = g_slice_alloc(sizeof(*sp));
 		*sp = format;
 		g_queue_push_tail(&output->format_list, sp);
@@ -718,7 +718,7 @@ static int parse_attribute_crypto(struct sdp_attribute *output) {
 			memcpy(c->mki + (c->mki_len - sizeof(u32)), &u32, sizeof(u32));
 	}
 
-	while (str_token_sep(&s, value_str, ' ') == 0) {
+	while (str_token_sep(&s, value_str, ' ')) {
 		if (!str_cmp(&s, "UNENCRYPTED_SRTCP"))
 			c->unencrypted_srtcp = 1;
 		else if (!str_cmp(&s, "UNENCRYPTED_SRTP"))
@@ -743,7 +743,7 @@ static int parse_attribute_rtcp(struct sdp_attribute *output) {
 	PARSE_INIT;
 
 	str portnum;
-	if (str_token_sep(&portnum, value_str, ' '))
+	if (!str_token_sep(&portnum, value_str, ' '))
 		goto err;
 	output->rtcp.port_num = str_to_i(&portnum, 0);
 	if (output->rtcp.port_num <= 0 || output->rtcp.port_num > 0xffff) {
@@ -828,9 +828,9 @@ static int parse_attribute_candidate(struct sdp_attribute *output, bool extended
 	if (extended) {
 		while (true) {
 			str field, value;
-			if (str_token_sep(&field, value_str, ' '))
+			if (!str_token_sep(&field, value_str, ' '))
 				break;
-			if (str_token_sep(&value, value_str, ' '))
+			if (!str_token_sep(&value, value_str, ' '))
 				break;
 			if (!str_cmp(&field, "ufrag"))
 				c->cand_parsed.ufrag = value;
diff --git a/lib/codeclib.c b/lib/codeclib.c
index 1c3c0a2a5..5bd1860c4 100644
--- a/lib/codeclib.c
+++ b/lib/codeclib.c
@@ -2739,8 +2739,8 @@ static void codeclib_key_value_parse(const str *instr, bool need_value,
 	// semicolon-separated key=value
 	str s = *instr;
 	str key, value;
-	while (str_token_sep(&value, &s, ';') == 0) {
-		if (str_token(&key, &value, '=')) {
+	while (str_token_sep(&value, &s, ';')) {
+		if (!str_token(&key, &value, '=')) {
 			if (need_value)
 				continue;
 			value = STR_NULL;
@@ -2858,7 +2858,7 @@ static void amr_parse_format_cb(str *key, str *token, void *data) {
 			break;
 		case CSH_LOOKUP("mode-set"):;
 			str mode;
-			while (str_token_sep(&mode, token, ',') == 0) {
+			while (str_token_sep(&mode, token, ',')) {
 				int m = str_to_i(&mode, -1);
 				if (m < 0 || m >= AMR_FT_TYPES)
 					continue;
@@ -3745,7 +3745,7 @@ void frame_fill_dtmf_samples(enum AVSampleFormat fmt, void *samples, unsigned in
 static unsigned int str_to_i_k(str *s) {
 	str intg;
 	str frac = *s;
-	if (!str_token(&intg, &frac, '.')) {
+	if (str_token(&intg, &frac, '.')) {
 		unsigned int ret = str_to_i(s, 0) * 1000;
 		if (frac.len > 1) // at most one decimal digit
 			frac.len = 1;
@@ -3803,7 +3803,7 @@ static void evs_parse_bw(enum evs_bw *minp, enum evs_bw *maxp, const str *token)
 static void evs_parse_br(unsigned int *minp, unsigned int *maxp, str *token) {
 	str min;
 	str max = *token;
-	if (!str_token(&min, &max, '-')) {
+	if (str_token(&min, &max, '-')) {
 		*minp = str_to_i_k(&min);
 		*maxp = str_to_i_k(&max);
 	}
@@ -3950,7 +3950,7 @@ static void evs_parse_format_cb(str *key, str *token, void *data) {
 			break;
 		case CSH_LOOKUP("mode-set"):;
 			str mode;
-			while (str_token_sep(&mode, token, ',') == 0) {
+			while (str_token_sep(&mode, token, ',')) {
 				int m = str_to_i(&mode, -1);
 				if (m < 0 || m > 8)
 					continue;
diff --git a/lib/str.h b/lib/str.h
index a749ff2d3..5084100d3 100644
--- a/lib/str.h
+++ b/lib/str.h
@@ -156,12 +156,12 @@ INLINE unsigned long long str_to_ui(const str *s, unsigned long long def);
 __attribute__((nonnull(1, 2)))
 ACCESS(write_only, 1)
 ACCESS(read_write, 2)
-INLINE int str_token(str *new_token, str *ori_and_remainder, int sep);
+INLINE bool str_token(str *new_token, str *ori_and_remainder, int sep);
 /* same as str_token but allows for a trailing non-empty token (e.g. "foo,bar" -> "foo", "bar" ) */
 __attribute__((nonnull(1, 2)))
 ACCESS(write_only, 1)
 ACCESS(read_write, 2)
-INLINE int str_token_sep(str *new_token, str *ori_and_remainder, int sep);
+INLINE bool str_token_sep(str *new_token, str *ori_and_remainder, int sep);
 /* copy a string to a regular C string buffer, limiting the max size */
 __attribute__((nonnull(1, 3)))
 ACCESS(write_only, 1, 2)
@@ -456,25 +456,25 @@ INLINE unsigned long long str_to_ui(const str *s, unsigned long long def) {
 	return ret;
 }
 
-INLINE int str_token(str *new_token, str *ori_and_remainder, int sep) {
+INLINE bool str_token(str *new_token, str *ori_and_remainder, int sep) {
 	*new_token = *ori_and_remainder;
 	if (!str_chr_str(ori_and_remainder, ori_and_remainder, sep))
-		return -1;
+		return false;
 	new_token->len = ori_and_remainder->s - new_token->s;
 	if (str_shift(ori_and_remainder, 1))
-		return -1;
-	return 0;
+		return false;
+	return true;
 }
 
-INLINE int str_token_sep(str *new_token, str *ori_and_remainder, int sep) {
+INLINE bool str_token_sep(str *new_token, str *ori_and_remainder, int sep) {
 	str ori = *ori_and_remainder;
-	if (!str_token(new_token, ori_and_remainder, sep))
-		return 0;
+	if (str_token(new_token, ori_and_remainder, sep))
+		return true;
 	// separator not found, use remainder as final token if not empty
 	if (!ori.len)
-		return -1;
+		return false;
 	*new_token = ori;
-	return 0;
+	return true;
 }
 
 INLINE size_t str_uri_encode(char *out, const str *in) {
diff --git a/perf-tester/main.c b/perf-tester/main.c
index 50d4c8f50..4777659ba 100644
--- a/perf-tester/main.c
+++ b/perf-tester/main.c
@@ -656,7 +656,7 @@ static void show_popup(const char *fmt, ...) {
 	str st = STR_INIT(s);
 	str token;
 	uint llen = 0;
-	while (str_token_sep(&token, &st, '\n') == 0) {
+	while (str_token_sep(&token, &st, '\n')) {
 		g_queue_push_tail(&lines, str_dup(&token));
 		llen = MAX(token.len, llen);
 	}
diff --git a/recording-daemon/metafile.c b/recording-daemon/metafile.c
index 0b4763b49..9ce7bd295 100644
--- a/recording-daemon/metafile.c
+++ b/recording-daemon/metafile.c
@@ -176,11 +176,11 @@ static void meta_metadata_parse(metafile_t *mf) {
 	str all_meta = STR_INIT(mf->metadata);
 	while (all_meta.len > 1) {
 		str token;
-		if (str_token_sep(&token, &all_meta, '|'))
+		if (!str_token_sep(&token, &all_meta, '|'))
 			break;
 
 		str key;
-		if (str_token(&key, &token, ':')) {
+		if (!str_token(&key, &token, ':')) {
 			// key:value separator not found, skip
 			continue;
 		}