diff --git a/SOURCES/main/kf2-srv b/SOURCES/main/kf2-srv
index f59fb8e..0ed06e9 100755
--- a/SOURCES/main/kf2-srv
+++ b/SOURCES/main/kf2-srv
@@ -43,7 +43,7 @@ readonly InstanceConfigTemplate="/etc/kf2-srv/instance.conf.template"
 
 readonly AppServerNum="232130"
 readonly AppClientNum="232090"
-readonly StrangeConstUID="17825793"
+readonly SteamConstB='17825793'
 readonly ServerBotLogin="srvbot"
 
 declare -a DiffNames
diff --git a/SOURCES/main/lib/ban.lib b/SOURCES/main/lib/ban.lib
index 24d136b..17be557 100644
--- a/SOURCES/main/lib/ban.lib
+++ b/SOURCES/main/lib/ban.lib
@@ -108,7 +108,7 @@ function ban_ID3 () # $1: ID3
 	do
 	(
 		local Config="$InstanceConfigDir/$Instance/LinuxServer-KFGame.ini"
-		local BanStr="(Uid=(A=$ID3,B=$StrangeConstUID))"
+		local BanStr="(Uid=(A=$ID3,B=$SteamConstB))"
 		local Service=$(service_name "$Instance")
 		if ! multini -gq "$Config" "Engine.AccessControl" "BannedIDs" "$BanStr"; then
 			echo "Add ban $ID3 to $Instance"
@@ -137,7 +137,7 @@ function unban_ID3 () # $1: ID3
 	do
 	(
 		local Config="$InstanceConfigDir/$Instance/LinuxServer-KFGame.ini"
-		local BanStr="(Uid=(A=$ID3,B=$StrangeConstUID))"
+		local BanStr="(Uid=(A=$ID3,B=$SteamConstB))"
 		local Service=$(service_name "$Instance")
 		if systemctl -q is-active $Service ; then
 			local PlainID=0
diff --git a/SOURCES/main/lib/playerids.lib b/SOURCES/main/lib/playerids.lib
index 1443fcc..5d50069 100644
--- a/SOURCES/main/lib/playerids.lib
+++ b/SOURCES/main/lib/playerids.lib
@@ -19,35 +19,42 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
-# conversion algorithm taken from here:
-# https://github.com/noobient/killinuxfloor/blob/master/share/killinuxfloor
-# thank bviktor for that :)
-function steamID3_to_steamID64 () # $1: ID3
+# WARNING:
+# Conversion works correctly for positive A/B for EGS, 
+# but still gives incorrect results if there are negative ones
+
+function steamID3_to_steamID64 () # $1: ID3 (A), $2: B
 {
-    # steamID64 = "7656" + (steamID3 + 1197960265728)
-    ID64=$1
-    ((ID64+=1197960265728))
-    ID64="7656${ID64}"
-    echo "$ID64"
+	local ID3="$1"
+	if [[ -z $2 ]]; then
+		local B="$SteamConstB"
+	else
+		local B="$2"
+	fi
+	
+	# SteamID64=B*2^32+SteamID3
+    echo $(($B*(2**32)+$ID3))
 }
 
-function steamID64_to_steamID3 () # $1: ID4
+function steamID64_to_steamID3 () # $1: ID64, $2: B
 {
-    # steamID3 = substr(steamID64, 4) - 1197960265728
-    ID3=${1:4}
-    ((ID3-=1197960265728))
-    echo "$ID3"
+	local ID64="$1"
+	if [[ -z $2 ]]; then
+		local B="$SteamConstB"
+	else
+		local B="$2"
+	fi
+	
+	# SteamID3=SteamID64-B*2^32
+    echo $(($ID64-$B*(2**32)))
 }
 
 function any_to_ID3 () # $1: ID3/ID64/Url
 {
 	if echo "$1" | grep -qP '^http.+'; then
-		local Xml=$(mktemp)
-		curl -ss "$1/?xml=1" > "$Xml"
-		local ID64=$(xmllint --xpath 'string(//steamID64/text())' "$Xml")
+		local ID64=$(curl -ss "$1/?xml=1" | xmllint --xpath 'string(//steamID64/text())' -)
 		local ID3=$(steamID64_to_steamID3 "$ID64") 
-		rm -f "$Xml"
-	elif [[ $(echo "$1" | wc -m) -eq 18 ]] && echo "$1" | grep -qP '^76561[0-9]+' ; then
+	elif [[ $(echo "$1" | wc -m) -eq 18 ]] && echo "$1" | grep -qP '^7656[0-9]+' ; then
 		local ID3=$(steamID64_to_steamID3 "$1")
 	else
 		local ID3="$1"
diff --git a/SPECS/kf2-srv.spec b/SPECS/kf2-srv.spec
index 95fa527..761ae09 100644
--- a/SPECS/kf2-srv.spec
+++ b/SPECS/kf2-srv.spec
@@ -1,7 +1,7 @@
 %global steamuser steam
 
 Name:       kf2-srv
-Version:    0.15.3
+Version:    0.15.4
 Release:    1%{dist}
 Summary:    Killing Floor 2 server
 Group:      Amusements/Games
@@ -101,6 +101,9 @@ if [[ $1 == 1 ]]; then # Install
 fi
 
 %changelog
+* Sat Aug 15 2020 GenZmeY <genzmey@gmail.com> - 0.15.4-1
+- replaced steamID3/steamID64 conversation algorithm.
+
 * Sat Aug 15 2020 GenZmeY <genzmey@gmail.com> - 0.15.3-1
 - fix 'find: Failed to restore initial working directory'.