diff --git a/freebox.py b/freebox.py
index fea3795..7b85c84 100644
--- a/freebox.py
+++ b/freebox.py
@@ -161,7 +161,7 @@ def authorize():
             except requests.exceptions.SSLError:
                 print("KO for", root_ca)
 
-        if self.root_ca is '':
+        if self.root_ca == '':
             print('Warning: using unsecure communication!')
             self.protocol = 'http'
             # re-compute URI using http
diff --git a/main.py b/main.py
index e523fda..214ea98 100755
--- a/main.py
+++ b/main.py
@@ -260,8 +260,9 @@ def print_config():
         print('graph_args --lower-limit 0')
         stations = get_wifi_stations()
         for station in stations:
-            print('{}.label {}'.format(station, station))
-            print('{}.draw AREASTACK'.format(station))
+            station_safe = station.replace(" ", "_")
+            print('{}.label {}'.format(station_safe, station))
+            print('{}.draw AREASTACK'.format(station_safe))
     elif mode == mode_wifi_bytes:
         print('graph_title Wifi bytes up/down')
         print('graph_scale yes')
@@ -411,7 +412,8 @@ def query_wifi_stations():
             value = 1
         else:
             value = 0
-        print('{}.value {}'.format(station, value))
+        station_safe = station.replace(" ", "_")
+        print('{}.value {}'.format(station_safe, value))
 
 def query_wifi_bytes():
     data = freebox.api('wifi/ap/0/stations/')
@@ -498,7 +500,8 @@ def query_switch_stations(interface):
             value = 1
         else:
             value = 0
-        print('{}.value {}'.format(station, value))
+        station_safe = station.replace(" ", "_")
+        print('{}.value {}'.format(station_safe, value))
 
 
 def query_rrd_data():