diff --git a/sj3dic/codecnv.c b/sj3dic/codecnv.c
index 968e980..fdf587c 100644
--- a/sj3dic/codecnv.c
+++ b/sj3dic/codecnv.c
@@ -81,7 +81,7 @@ unsigned char	*s;
 		unsigned short	i;
 		unsigned char	*d = s;
 
-		while (i = *s++) {
+		while ((i = *s++)) {
 			if (iseuckana(i)) {
 				if (*s) {
 					*d++ = *s++;
diff --git a/sj3dic/dictmake.c b/sj3dic/dictmake.c
index 0aa3bbb..1ee0c74 100644
--- a/sj3dic/dictmake.c
+++ b/sj3dic/dictmake.c
@@ -157,7 +157,7 @@ char	*input;
 		fp = stdin;
 
 	while (fgets((char *)buf, sizeof(buf), fp)) {
-		if (p = (unsigned char *)strchr((char *)buf, '\n'))
+		if ((p = (unsigned char *)strchr((char *)buf, '\n')))
 			*p = '\0';
 		else {
 			do {
diff --git a/sj3dic/sj3dic.c b/sj3dic/sj3dic.c
index c208200..68852ad 100644
--- a/sj3dic/sj3dic.c
+++ b/sj3dic/sj3dic.c
@@ -110,8 +110,8 @@ main(int argc, char** argv)
 	make_dicname();
 
 	/* XXX: is this progname intentional? or old variable left? */
-	/* if (err = sj3_open(serv_name, user_name, prog_name)) */
-	if (err = sj3_open(serv_name, user_name))
+	/* if ((err = sj3_open(serv_name, user_name, prog_name))) */
+	if ((err = sj3_open(serv_name, user_name)))
 		_open_error(err);
 
 	switch (mode) {
@@ -126,7 +126,7 @@ main(int argc, char** argv)
 		break;
 	}
 
-	if (err = sj3_close()) _close_error(err);
+	if ((err = sj3_close())) _close_error(err);
 }
 
 static void
diff --git a/sj3lib/level1.c b/sj3lib/level1.c
index c839ead..24d872a 100644
--- a/sj3lib/level1.c
+++ b/sj3lib/level1.c
@@ -424,7 +424,7 @@ open_inet(char* host)
 		return ERROR;
 	}
 
-	if (sp = getservbyname(sj3_port_name, "tcp"))
+	if ((sp = getservbyname(sj3_port_name, "tcp")))
 		port = ntohs(sp -> s_port);
 	else
 		port = sj3_port_number;
@@ -557,7 +557,7 @@ sj3_make_connection(
 				     userlen, put_string, prog, proglen, NULL, NULL, 0) == ERROR)
 			    return ERROR;
 		}
-		if (tmp = get_int()) {
+		if ((tmp = get_int())) {
 			sj3_erase_connection(client);
 			sj3_error_number = tmp;
 			return ERROR;
@@ -577,7 +577,7 @@ sj3_make_connection(
 	put_cmd(SJ3_STDYSIZE);
         if (put_flush() == ERROR) return ERROR;
 
-	if (tmp = get_int()) {
+	if ((tmp = get_int())) {
 		sj3_erase_connection(client);
 		sj3_error_number = tmp;
 		return ERROR;
@@ -635,7 +635,7 @@ sj3_open_dictionary(
 	    return ERROR;
 	}
 
-	if (sj3_error_number = get_int()) return 0;
+	if ((sj3_error_number = get_int())) return 0;
         res = get_int();
         return ReadErrorFlag ? ERROR : res;
 }
@@ -649,7 +649,7 @@ sj3_close_dictionary(SJ3_CLIENT_ENV* client, long dicid)
 	put_int(dicid);
         if (put_flush() == ERROR) return ERROR;
 
-	if (sj3_error_number = get_int()) return ERROR;
+	if ((sj3_error_number = get_int())) return ERROR;
         return ReadErrorFlag ? ERROR : 0;
 }
 
@@ -679,7 +679,7 @@ sj3_open_study_file(
 	    return ERROR;
 	}
 
-	if (sj3_error_number = get_int()) return ERROR;
+	if ((sj3_error_number = get_int())) return ERROR;
         return ReadErrorFlag ? ERROR : 0;
 }
 
@@ -691,7 +691,7 @@ sj3_close_study_file(SJ3_CLIENT_ENV* client)
 	put_cmd(SJ3_CLOSESTDY);
         if (put_flush() == ERROR) return ERROR;
 
-	if (sj3_error_number = get_int()) return ERROR;
+	if ((sj3_error_number = get_int())) return ERROR;
         return ReadErrorFlag ? ERROR : 0;
 }
 
@@ -704,7 +704,7 @@ sj3_get_id_size(SJ3_CLIENT_ENV* client)
 	put_cmd(SJ3_STDYSIZE);
         if (put_flush() == ERROR) return ERROR;
 
-	if (sj3_error_number = get_int()) return ERROR;
+	if ((sj3_error_number = get_int())) return ERROR;
 	cliptr -> stdy_size = get_int();
         return ReadErrorFlag ? ERROR : cliptr -> stdy_size;
 }
@@ -718,7 +718,7 @@ sj3_lock_server(SJ3_CLIENT_ENV* client)
 	put_cmd(SJ3_LOCK);
         if (put_flush() == ERROR) return ERROR;
 
-	if (sj3_error_number = get_int()) return ERROR;
+	if ((sj3_error_number = get_int())) return ERROR;
         return ReadErrorFlag ? ERROR : 0;
 }
 
@@ -730,7 +730,7 @@ sj3_unlock_server(SJ3_CLIENT_ENV *client)
 	put_cmd(SJ3_UNLOCK);
         if (put_flush() == ERROR) return ERROR;
 
-	if (sj3_error_number = get_int()) return ERROR;
+	if ((sj3_error_number = get_int())) return ERROR;
         return ReadErrorFlag ? ERROR : 0;
 }
 
@@ -770,7 +770,7 @@ sj3_ikkatu_henkan(
 	    return ERROR;
 	}
 
-	if (sj3_error_number = get_int()) return ERROR;
+	if ((sj3_error_number = get_int())) return ERROR;
 
 	result = get_int();
 
@@ -778,7 +778,7 @@ sj3_ikkatu_henkan(
 	result = 0;
 	stysiz = cliptr -> stdy_size;
 	len1 =  1 + stysiz + 1 + 1;	
-	while (c = get_byte()) {
+	while ((c = get_byte())) {
 
 		top = dst;		
 		if (dstsiz < len1) goto error1;
@@ -787,7 +787,7 @@ sj3_ikkatu_henkan(
 		dst = get_ndata(dst, stysiz);
 		dstsiz -= (stysiz + 1);
 
-		while (c = get_byte()) {
+		while ((c = get_byte())) {
 			if (dstsiz-- < 3) goto error2;
 			*dst++ = c;
 		}
@@ -841,7 +841,7 @@ sj3_bunsetu_henkan(
             return ERROR;
 	}
 
-	if (sj3_error_number = get_int()) return ERROR;
+	if ((sj3_error_number = get_int())) return ERROR;
 
 	result = get_int();
 	get_string( get_ndata(kanji, cliptr -> stdy_size) );
@@ -866,7 +866,7 @@ sj3_bunsetu_jikouho(
 	put_int(mode);
         if (put_flush() == ERROR) return ERROR;
 
-	if (sj3_error_number = get_int()) return ERROR;
+	if ((sj3_error_number = get_int())) return ERROR;
 
 	result = get_int();
 	get_string( get_ndata(kanji, cliptr -> stdy_size) );
@@ -889,7 +889,7 @@ sj3_bunsetu_maekouho(
 	put_int(mode);
         if (put_flush() == ERROR) return ERROR;
 
-	if (sj3_error_number = get_int()) return ERROR;
+	if ((sj3_error_number = get_int())) return ERROR;
 
 	result = get_int();
 	get_string( get_ndata(kanji, cliptr -> stdy_size) );
@@ -925,7 +925,7 @@ sj3_bunsetu_kouhosuu(
             return ERROR;
 	}
 
-	if (sj3_error_number = get_int()) return ERROR;
+	if ((sj3_error_number = get_int())) return ERROR;
 
 	result = get_int();
         return ReadErrorFlag ? ERROR : result;
@@ -960,7 +960,7 @@ sj3_bunsetu_zenkouho(
             return ERROR;
 	}
 
-	if (sj3_error_number = get_int()) return ERROR;
+	if ((sj3_error_number = get_int())) return ERROR;
 
 	while (get_int()) {
                 get_ndata(&(douon -> dcid), cliptr -> stdy_size);
@@ -993,7 +993,7 @@ sj3_tango_gakusyuu(SJ3_CLIENT_ENV* client, SJ3_STUDYREC* stdy)
 	}
 
 
-	if (sj3_error_number = get_int()) return ERROR;
+	if ((sj3_error_number = get_int())) return ERROR;
         return ReadErrorFlag ? ERROR : 0;
 }
 
@@ -1030,7 +1030,7 @@ sj3_bunsetu_gakusyuu(
             return ERROR;
 	}
 
-	if (sj3_error_number = get_int()) return ERROR;
+	if ((sj3_error_number = get_int())) return ERROR;
         return ReadErrorFlag ? ERROR : 0;
 }
 
@@ -1069,7 +1069,7 @@ sj3_tango_touroku(
             return ERROR;
 	}
 
-	if (sj3_error_number = get_int()) return ERROR;
+	if ((sj3_error_number = get_int())) return ERROR;
         return ReadErrorFlag ? ERROR : 0;
 }
 
@@ -1107,7 +1107,7 @@ sj3_tango_sakujo(
             return ERROR;
 	}
 
-	if (sj3_error_number = get_int()) return ERROR;
+	if ((sj3_error_number = get_int())) return ERROR;
         return ReadErrorFlag ? ERROR : 0;
 }
 
@@ -1130,7 +1130,7 @@ sj3_tango_syutoku(
 	put_int(dicid);
         if (put_flush() == ERROR) return ERROR;
 
-	if (sj3_error_number = get_int()) return ERROR;
+	if ((sj3_error_number = get_int())) return ERROR;
 
 	p = get_string(buf);
 	p = get_string(p);
@@ -1156,7 +1156,7 @@ sj3_tango_jikouho(
 	put_int(dicid);
         if (put_flush() == ERROR) return ERROR;
 
-	if (sj3_error_number = get_int()) return ERROR;
+	if ((sj3_error_number = get_int())) return ERROR;
 
 	p = get_string(buf);
 	p = get_string(p);
@@ -1182,7 +1182,7 @@ sj3_tango_maekouho(
 	put_int(dicid);
         if (put_flush() == ERROR) return ERROR;
 
-	if (sj3_error_number = get_int()) return ERROR;
+	if ((sj3_error_number = get_int())) return ERROR;
 
 	p = get_string(buf);
 	p = get_string(p);
@@ -1221,7 +1221,7 @@ sj3_make_dict_file(
             return ERROR;
 	}
 
-	if (sj3_error_number = get_int()) return ERROR;
+	if ((sj3_error_number = get_int())) return ERROR;
         return ReadErrorFlag ? ERROR : 0;
 }
 
@@ -1256,7 +1256,7 @@ sj3_make_study_file(
             return ERROR;
 	}
 
-	if (sj3_error_number = get_int()) return ERROR;
+	if ((sj3_error_number = get_int())) return ERROR;
         return ReadErrorFlag ? ERROR : 0;
 }
 
@@ -1282,7 +1282,7 @@ sj3_make_directory(SJ3_CLIENT_ENV* client, char* path)
 	}
 	  
 
-	if (sj3_error_number = get_int()) return ERROR;
+	if ((sj3_error_number = get_int())) return ERROR;
         return ReadErrorFlag ? ERROR : 0;
 }
 
@@ -1360,7 +1360,7 @@ sj3_quit(SJ3_CLIENT_ENV* client)
 	put_cmd(SJ3_QUIT);
         if (put_flush() == ERROR) return ERROR;
 
-	if (sj3_error_number = get_int()) return ERROR;
+	if ((sj3_error_number = get_int())) return ERROR;
         return ReadErrorFlag ? ERROR : 0;
 }
 
@@ -1372,7 +1372,7 @@ sj3_kill(SJ3_CLIENT_ENV* client)
 	put_cmd(SJ3_KILL);
         if (put_flush() == ERROR) return ERROR;
 
-	if (sj3_error_number = get_int()) return ERROR;
+	if ((sj3_error_number = get_int())) return ERROR;
         return ReadErrorFlag ? ERROR : 0;
 }