diff --git a/src/main/java/im/conversations/android/xmpp/sasl/DigestMd5.java b/src/main/java/im/conversations/android/xmpp/sasl/DigestMd5.java
index d1e2b914b..dc4135d1d 100644
--- a/src/main/java/im/conversations/android/xmpp/sasl/DigestMd5.java
+++ b/src/main/java/im/conversations/android/xmpp/sasl/DigestMd5.java
@@ -1,6 +1,7 @@
 package im.conversations.android.xmpp.sasl;
 
 import android.util.Base64;
+import com.google.common.base.Strings;
 import eu.siacs.conversations.utils.CryptoHelper;
 import im.conversations.android.database.model.Account;
 import im.conversations.android.database.model.Credential;
@@ -54,7 +55,7 @@ public class DigestMd5 extends SaslMechanism {
                                     + ":"
                                     + account.address.getDomain()
                                     + ":"
-                                    + credential.password;
+                                    + Strings.nullToEmpty(credential.password);
                     final MessageDigest md = MessageDigest.getInstance("MD5");
                     final byte[] y = md.digest(x.getBytes(Charset.defaultCharset()));
                     final String cNonce = CryptoHelper.random(100);
diff --git a/src/main/java/im/conversations/android/xmpp/sasl/Plain.java b/src/main/java/im/conversations/android/xmpp/sasl/Plain.java
index d41c07629..3da877e1e 100644
--- a/src/main/java/im/conversations/android/xmpp/sasl/Plain.java
+++ b/src/main/java/im/conversations/android/xmpp/sasl/Plain.java
@@ -1,6 +1,7 @@
 package im.conversations.android.xmpp.sasl;
 
 import android.util.Base64;
+import com.google.common.base.Strings;
 import im.conversations.android.database.model.Account;
 import im.conversations.android.database.model.Credential;
 import java.nio.charset.Charset;
@@ -31,6 +32,7 @@ public class Plain extends SaslMechanism {
 
     @Override
     public String getClientFirstMessage(final SSLSocket sslSocket) {
-        return getMessage(account.address.getEscapedLocal(), credential.password);
+        return getMessage(
+                account.address.getEscapedLocal(), Strings.nullToEmpty(credential.password));
     }
 }
diff --git a/src/main/java/im/conversations/android/xmpp/sasl/ScramMechanism.java b/src/main/java/im/conversations/android/xmpp/sasl/ScramMechanism.java
index 99f500d75..a1790cc28 100644
--- a/src/main/java/im/conversations/android/xmpp/sasl/ScramMechanism.java
+++ b/src/main/java/im/conversations/android/xmpp/sasl/ScramMechanism.java
@@ -3,6 +3,7 @@ package im.conversations.android.xmpp.sasl;
 import android.util.Base64;
 import com.google.common.base.CaseFormat;
 import com.google.common.base.Objects;
+import com.google.common.base.Strings;
 import com.google.common.cache.Cache;
 import com.google.common.cache.CacheBuilder;
 import com.google.common.hash.HashFunction;
@@ -215,7 +216,7 @@ abstract class ScramMechanism extends SaslMechanism {
                 try {
                     keys =
                             getKeyPair(
-                                    CryptoHelper.saslPrep(credential.password),
+                                    CryptoHelper.saslPrep(Strings.nullToEmpty(credential.password)),
                                     salt,
                                     iterationCount);
                 } catch (ExecutionException e) {