diff --git a/app/build.gradle b/app/build.gradle
index 4172c2a5..4a9173b8 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -10,7 +10,7 @@ apply plugin: 'com.android.application'
 
 android {
     compileSdkVersion 24
-    buildToolsVersion '24.0.3'
+    buildToolsVersion '25.0.0'
 
     defaultConfig {
         applicationId "at.bitfire.davdroid"
diff --git a/app/src/main/java/at/bitfire/davdroid/syncadapter/SyncAdapterService.java b/app/src/main/java/at/bitfire/davdroid/syncadapter/SyncAdapterService.java
index 34a1ce21..4403f5a2 100644
--- a/app/src/main/java/at/bitfire/davdroid/syncadapter/SyncAdapterService.java
+++ b/app/src/main/java/at/bitfire/davdroid/syncadapter/SyncAdapterService.java
@@ -99,7 +99,7 @@ public abstract class SyncAdapterService extends Service {
                 String onlySSID = settings.getSyncWifiOnlySSID();
                 if (onlySSID != null) {
                     onlySSID = "\"" + onlySSID + "\"";
-                    WifiManager wifi = (WifiManager)getContext().getSystemService(WIFI_SERVICE);
+                    WifiManager wifi = (WifiManager)getContext().getApplicationContext().getSystemService(WIFI_SERVICE);
                     WifiInfo info = wifi.getConnectionInfo();
                     if (info == null || !onlySSID.equals(info.getSSID())) {
                         App.log.info("Connected to wrong WiFi network (" + info.getSSID() + ", required: " + onlySSID + "), ignoring");
diff --git a/cert4android b/cert4android
index 7b8f52ad..30b8bc58 160000
--- a/cert4android
+++ b/cert4android
@@ -1 +1 @@
-Subproject commit 7b8f52ad55dbc62b57a59f783ac79e8db567e4ad
+Subproject commit 30b8bc58ce3dccc8c41af0b4d224a3b5aafd5979
diff --git a/dav4android b/dav4android
index 86d35469..fff1c904 160000
--- a/dav4android
+++ b/dav4android
@@ -1 +1 @@
-Subproject commit 86d3546970d3db3df2b50a2c31a356efb2210fbd
+Subproject commit fff1c904582c6d1cf0c4e9b3f64245138e395a03
diff --git a/ical4android b/ical4android
index fe0b1bf5..cca311e3 160000
--- a/ical4android
+++ b/ical4android
@@ -1 +1 @@
-Subproject commit fe0b1bf5e85cb011149716cd9ea10482fcbbcf4e
+Subproject commit cca311e3dabf7f6450964edd2060a811115a7443
diff --git a/vcard4android b/vcard4android
index ce7a2f2c..eae31dac 160000
--- a/vcard4android
+++ b/vcard4android
@@ -1 +1 @@
-Subproject commit ce7a2f2cb2928673eb8ff03f68acd371211f601c
+Subproject commit eae31dac277c1b1d85f5870829fbc0ff1cb49735