diff --git a/qnapstats/qnap_stats.py b/qnapstats/qnap_stats.py
index 1758738..4987182 100644
--- a/qnapstats/qnap_stats.py
+++ b/qnapstats/qnap_stats.py
@@ -229,8 +229,8 @@ def get_system_stats(self):
                 "name": root["server_name"],
                 "model": resp["model"]["displayModelName"],
                 "serial_number": root["serial_number"],
-                "temp_c": int(root["sys_tempc"]),
-                "temp_f": int(root["sys_tempf"]),
+                "temp_c": int(root["sys_tempc"]) if "sys_tempc" in root else None,
+                "temp_f": int(root["sys_tempf"]) if "sys_tempf" in root else None,
                 "timezone": root["timezone"],
             },
             "firmware": {
diff --git a/tests/responses/TS-X53-4.5.4-faulty-sys-sensor/login.xml b/tests/responses/TS-X53-4.5.4-faulty-sys-sensor/login.xml
new file mode 100644
index 0000000..442260e
--- /dev/null
+++ b/tests/responses/TS-X53-4.5.4-faulty-sys-sensor/login.xml
@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<!-- This file was actually copied from TS-451-4.2.2 -->
+<QDocRoot version="1.0">
+    <doQuick><![CDATA[]]></doQuick>
+    <is_booting><![CDATA[0]]></is_booting>
+    <mediaReady><![CDATA[1]]></mediaReady>
+    <SMBFW><![CDATA[0]]></SMBFW>
+    <authPassed><![CDATA[1]]></authPassed>
+    <isAdmin><![CDATA[1]]></isAdmin>
+    <username><![CDATA[admin]]></username>
+    <groupname><![CDATA[administrators]]></groupname>
+    <ts><![CDATA[43397768]]></ts>
+    <fwNotice><![CDATA[0]]></fwNotice>
+    <SUID><![CDATA[29935b343f5c12b1f584b865ee60e386]]></SUID>
+    <title><![CDATA[]]></title>
+    <content><![CDATA[]]></content>
+    <psType><![CDATA[1]]></psType>
+    <showVersion><![CDATA[0]]></showVersion>
+    <show_link><![CDATA[1]]></show_link>
+</QDocRoot>
diff --git a/tests/responses/TS-X53-4.5.4-faulty-sys-sensor/login_with_get.xml b/tests/responses/TS-X53-4.5.4-faulty-sys-sensor/login_with_get.xml
new file mode 100644
index 0000000..4761d49
--- /dev/null
+++ b/tests/responses/TS-X53-4.5.4-faulty-sys-sensor/login_with_get.xml
@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<!-- This file was actually copied from TS-451-4.2.2 -->
+<QDocRoot version="1.0">
+<doQuick><![CDATA[]]></doQuick><is_booting><![CDATA[0]]></is_booting><mediaReady><![CDATA[1]]></mediaReady><SMBFW><![CDATA[0]]></SMBFW><authPassed><![CDATA[1]]></authPassed><authSid><![CDATA[12345]]></authSid><isAdmin><![CDATA[1]]></isAdmin><username><![CDATA[admin]]></username><groupname><![CDATA[administrators]]></groupname><ts><![CDATA[43397768]]></ts><fwNotice><![CDATA[0]]></fwNotice><SUID><![CDATA[29935b343f5c12b1f584b865ee60e386]]></SUID><title><![CDATA[]]></title><content><![CDATA[]]></content><psType><![CDATA[1]]></psType><showVersion><![CDATA[0]]></showVersion><show_link><![CDATA[1]]></show_link></QDocRoot>
\ No newline at end of file
diff --git a/tests/responses/TS-X53-4.5.4-faulty-sys-sensor/systemstats.json b/tests/responses/TS-X53-4.5.4-faulty-sys-sensor/systemstats.json
new file mode 100644
index 0000000..687ea74
--- /dev/null
+++ b/tests/responses/TS-X53-4.5.4-faulty-sys-sensor/systemstats.json
@@ -0,0 +1 @@
+{"cpu": {"model": null, "temp_c": null, "temp_f": null, "usage_percent": 48.5}, "dns": ["192.168.1.1"], "firmware": {"build": "20170121", "build_time": "21-01-2017", "patch": "0", "version": "4.2.3"}, "memory": {"free": 60.8, "total": 249.6}, "nics": {"eth0": {"err_packets": 0, "ip": "192.168.1.101", "link_status": "Up", "mac": "00:08:9B:C1:80:6A", "mask": "255.255.255.0", "max_speed": 1000, "rx_packets": 193439491, "tx_packets": 123234929, "usage": "DHCP"}, "eth1": {"err_packets": 0, "ip": "0.0.0.0", "link_status": "Down", "mac": "00:08:9B:C1:80:6B", "mask": "0.0.0.0", "max_speed": 1000, "rx_packets": 0, "tx_packets": 0, "usage": "DHCP"}}, "sysfans": {}, "system": {"model": "TS-253 Pro", "name": "hornbill", "serial_number": "MYSERIAL", "temp_c": null, "temp_f": null, "timezone": "(GMT+01:00) Amsterdam, Berlin, Bern, Rome, Stockholm, Vienna"}, "uptime": {"days": 13, "hours": 17, "minutes": 47, "seconds": 48}}
\ No newline at end of file
diff --git a/tests/responses/TS-X53-4.5.4-faulty-sys-sensor/systemstats.xml b/tests/responses/TS-X53-4.5.4-faulty-sys-sensor/systemstats.xml
new file mode 100644
index 0000000..27f6fbd
--- /dev/null
+++ b/tests/responses/TS-X53-4.5.4-faulty-sys-sensor/systemstats.xml
@@ -0,0 +1,31 @@
+<QDocRoot version="1.0">
+<authPassed><![CDATA[1]]></authPassed><model><modelName><![CDATA[TS-X53]]></modelName><internalModelName><![CDATA[TS-253Pro]]></internalModelName><platform><![CDATA[TS-NASX86]]></platform><customModelName><![CDATA[]]></customModelName><displayModelName><![CDATA[TS-253 Pro]]></displayModelName><storage_v2>0</storage_v2>
+</model>
+<firmware><version><![CDATA[4.2.3]]></version><build><![CDATA[20170121]]></build><patch><![CDATA[0]]></patch><buildTime><![CDATA[21-01-2017]]></buildTime></firmware>
+<specVersion><![CDATA[1.0]]></specVersion><hostname><![CDATA[MYHOSTNAME]]></hostname><DemoSiteSuppurt><![CDATA[no]]></DemoSiteSuppurt><customLogo><customFrontLogo><![CDATA[]]></customFrontLogo><customLoginLogo><![CDATA[]]></customLoginLogo></customLogo>
+<func><name><![CDATA[S_MENU_40]]></name><ownContent><root><timezone><![CDATA[(GMT+01:00) Amsterdam, Berlin, Bern, Rome, Stockholm, Vienna]]></timezone><cpu_usage><![CDATA[48.5 %]]></cpu_usage><total_memory><![CDATA[249.6]]></total_memory><free_memory><![CDATA[60.8]]></free_memory><nic_cnt><![CDATA[2]]></nic_cnt><rx_packet1>193439491</rx_packet1>
+<tx_packet1>123234929</tx_packet1>
+<err_packet1>0</err_packet1>
+<eth_status1>1</eth_status1>
+<eth_max_speed1>1000</eth_max_speed1>
+<eth_ip1>192.168.1.101</eth_ip1>
+<eth_mask1>255.255.255.0</eth_mask1>
+<eth_mac1>00:08:9B:C1:80:6A</eth_mac1>
+<eth_usage1>DHCP</eth_usage1>
+<rx_packet2>0</rx_packet2>
+<tx_packet2>0</tx_packet2>
+<err_packet2>0</err_packet2>
+<eth_status2>0</eth_status2>
+<eth_max_speed2>1000</eth_max_speed2>
+<eth_ip2>0.0.0.0</eth_ip2>
+<eth_mask2>0.0.0.0</eth_mask2>
+<eth_mac2>00:08:9B:C1:80:6B</eth_mac2>
+<eth_usage2>DHCP</eth_usage2>
+<ipv6Enable><![CDATA[0]]></ipv6Enable><dnsInfo><DNS_LIST><![CDATA[ 192.168.1.1
+]]></DNS_LIST></dnsInfo>
+<WirelessSupport><![CDATA[1]]></WirelessSupport><Error><![CDATA[1]]></Error><ThunderboltSupport><![CDATA[0]]></ThunderboltSupport><uptime_day><![CDATA[13]]></uptime_day><uptime_hour><![CDATA[17]]></uptime_hour><uptime_min><![CDATA[47]]></uptime_min><uptime_sec><![CDATA[48]]></uptime_sec><HDTempWarnT><![CDATA[55]]></HDTempWarnT><HDTempErrT><![CDATA[60]]></HDTempErrT><SSDTempWarnT><![CDATA[65]]></SSDTempWarnT><SSDTempErrT><![CDATA[70]]></SSDTempErrT><SysTempWarnT><![CDATA[57]]></SysTempWarnT><SysTempErrT><![CDATA[70]]></SysTempErrT><sysfan_count>0</sysfan_count>
+<serial_number>MYSERIAL</serial_number>
+<server_name><![CDATA[hornbill]]></server_name><codepage><![CDATA[437]]></codepage></root>
+</ownContent>
+</func>
+</QDocRoot>
\ No newline at end of file