diff --git a/F-Droid/src/org/fdroid/fdroid/net/WifiStateChangeService.java b/F-Droid/src/org/fdroid/fdroid/net/WifiStateChangeService.java
index 860371ec8..5befdbaf2 100644
--- a/F-Droid/src/org/fdroid/fdroid/net/WifiStateChangeService.java
+++ b/F-Droid/src/org/fdroid/fdroid/net/WifiStateChangeService.java
@@ -207,7 +207,8 @@ public class WifiStateChangeService extends Service {
                         // the following methods were not added until android-9/Gingerbread
                         for (InterfaceAddress address : netIf.getInterfaceAddresses()) {
                             if (inetAddress.equals(address.getAddress()) && !TextUtils.isEmpty(FDroidApp.ipAddressString)) {
-                                String cidr = String.format("%s/%d", FDroidApp.ipAddressString, address.getNetworkPrefixLength());
+                                String cidr = String.format(Locale.ENGLISH, "%s/%d",
+                                        FDroidApp.ipAddressString, address.getNetworkPrefixLength());
                                 FDroidApp.subnetInfo = (new SubnetUtils(cidr)).getInfo();
                                 break;
                             }