diff --git a/app/src/main/java/com/github/yeriomin/yalpstore/AppListViewBinder.java b/app/src/main/java/com/github/yeriomin/yalpstore/AppListViewBinder.java
index 14eb40d36..b4493102a 100644
--- a/app/src/main/java/com/github/yeriomin/yalpstore/AppListViewBinder.java
+++ b/app/src/main/java/com/github/yeriomin/yalpstore/AppListViewBinder.java
@@ -33,7 +33,7 @@ class AppListViewBinder implements SimpleAdapter.ViewBinder {
             ImageDownloadTask task = new ImageDownloadTask();
             task.setView(view);
             task.execute((String) drawableOrUrl);
-        } else if (null != drawableOrUrl) {
+        } else {
             view.setImageDrawable((Drawable) drawableOrUrl);
         }
         return true;
diff --git a/app/src/main/java/com/github/yeriomin/yalpstore/BitmapManager.java b/app/src/main/java/com/github/yeriomin/yalpstore/BitmapManager.java
index 283b09201..4c7b27331 100644
--- a/app/src/main/java/com/github/yeriomin/yalpstore/BitmapManager.java
+++ b/app/src/main/java/com/github/yeriomin/yalpstore/BitmapManager.java
@@ -28,7 +28,7 @@ public class BitmapManager {
     private Context context;
 
     static {
-        HttpsURLConnection.setDefaultHostnameVerifier(new NullHostNameVerifier());
+        HttpsURLConnection.setDefaultHostnameVerifier(HttpsURLConnection.getDefaultHostnameVerifier());
         try {
             SSLContext sslContext = SSLContext.getInstance("TLS");
             sslContext.init(null, new X509TrustManager[]{new NullX509TrustManager()}, new SecureRandom());
diff --git a/app/src/main/java/com/github/yeriomin/yalpstore/NullHostNameVerifier.java b/app/src/main/java/com/github/yeriomin/yalpstore/NullHostNameVerifier.java
deleted file mode 100644
index 0e4412bef..000000000
--- a/app/src/main/java/com/github/yeriomin/yalpstore/NullHostNameVerifier.java
+++ /dev/null
@@ -1,12 +0,0 @@
-package com.github.yeriomin.yalpstore;
-
-import javax.net.ssl.HostnameVerifier;
-import javax.net.ssl.SSLSession;
-
-class NullHostNameVerifier implements HostnameVerifier {
-
-    @Override
-    public boolean verify(String hostname, SSLSession session) {
-        return true;
-    }
-}
diff --git a/app/src/main/java/com/github/yeriomin/yalpstore/NullX509TrustManager.java b/app/src/main/java/com/github/yeriomin/yalpstore/NullX509TrustManager.java
index 1a3a03049..d1cb35f13 100644
--- a/app/src/main/java/com/github/yeriomin/yalpstore/NullX509TrustManager.java
+++ b/app/src/main/java/com/github/yeriomin/yalpstore/NullX509TrustManager.java
@@ -1,17 +1,27 @@
 package com.github.yeriomin.yalpstore;
 
+import java.security.cert.CertificateException;
+
 import javax.net.ssl.X509TrustManager;
 
 class NullX509TrustManager implements X509TrustManager {
 
     @Override
     public void checkClientTrusted(java.security.cert.X509Certificate[] x509Certificates, String s) throws java.security.cert.CertificateException {
-        // not implemented
+        try {
+            x509Certificates[0].checkValidity();
+        } catch (Exception e) {
+            throw new CertificateException("Certificate not valid or trusted.");
+        }
     }
 
     @Override
     public void checkServerTrusted(java.security.cert.X509Certificate[] x509Certificates, String s) throws java.security.cert.CertificateException {
-        // not implemented
+        try {
+            x509Certificates[0].checkValidity();
+        } catch (Exception e) {
+            throw new CertificateException("Certificate not valid or trusted.");
+        }
     }
 
     @Override
diff --git a/app/src/main/java/com/github/yeriomin/yalpstore/PreferenceLanguageFragment.java b/app/src/main/java/com/github/yeriomin/yalpstore/PreferenceLanguageFragment.java
index b8354e6eb..08e69cc7b 100644
--- a/app/src/main/java/com/github/yeriomin/yalpstore/PreferenceLanguageFragment.java
+++ b/app/src/main/java/com/github/yeriomin/yalpstore/PreferenceLanguageFragment.java
@@ -37,7 +37,7 @@ public class PreferenceLanguageFragment extends PreferenceListFragment {
         Map<String, String> languages = new HashMap<>();
         for (Locale locale: Locale.getAvailableLocales()) {
             String displayName = locale.getDisplayName();
-            displayName = displayName.substring(0, 1).toUpperCase() + displayName.substring(1);
+            displayName = displayName.substring(0, 1).toUpperCase(Locale.getDefault()) + displayName.substring(1);
             languages.put(locale.toString(), displayName);
         }
         languages = Util.sort(languages);