diff --git a/scm-core/src/main/java/sonia/scm/web/filter/BasicAuthenticationFilter.java b/scm-core/src/main/java/sonia/scm/web/filter/BasicAuthenticationFilter.java
index 38532ff3ac..ba3bcbe12d 100644
--- a/scm-core/src/main/java/sonia/scm/web/filter/BasicAuthenticationFilter.java
+++ b/scm-core/src/main/java/sonia/scm/web/filter/BasicAuthenticationFilter.java
@@ -35,6 +35,7 @@ package sonia.scm.web.filter;
 
 //~--- non-JDK imports --------------------------------------------------------
 
+import com.google.common.base.Objects;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
 import com.google.inject.Singleton;
@@ -59,6 +60,7 @@ import sonia.scm.web.security.WebSecurityContext;
 import com.sun.jersey.core.util.Base64;
 
 import java.io.IOException;
+import java.io.UnsupportedEncodingException;
 
 import java.util.Set;
 
@@ -87,6 +89,9 @@ public class BasicAuthenticationFilter extends AutoLoginFilter
   /** marker for failed authentication */
   private static final String ATTRIBUTE_FAILED_AUTH = "sonia.scm.auth.failed";
 
+  /** default encoding to decode basic authentication header */
+  private static final String DEFAULT_ENCODING = "ISO-8859-1";
+
   /** the logger for BasicAuthenticationFilter */
   private static final Logger logger =
     LoggerFactory.getLogger(BasicAuthenticationFilter.class);
@@ -271,13 +276,14 @@ public class BasicAuthenticationFilter extends AutoLoginFilter
    * @param authentication
    *
    * @return
+   *
+   * @throws IOException
    */
   private User authenticate(HttpServletRequest request,
     HttpServletResponse response, Subject subject, String authentication)
+    throws IOException
   {
-    String token = authentication.substring(6);
-
-    token = new String(Base64.decode(token.getBytes()));
+    String token = decodeAuthenticationHeader(request, authentication);
 
     int index = token.indexOf(CREDENTIAL_SEPARATOR);
     User user = null;
@@ -331,6 +337,47 @@ public class BasicAuthenticationFilter extends AutoLoginFilter
     return user;
   }
 
+  /**
+   * Decode base64 of the basic authentication header. The method tries to use
+   * the charset provided by the request, if the request does not send an
+   * contain an encoding the method will be fallback to ISO-8859-1.
+   *
+   *
+   * @param request http request
+   * @param authentication base64 encoded basic authentication string
+   *
+   * @return decoded basic authentication header
+   *
+   * @see <a href="http://goo.gl/tZEBS3">issue 627</a>
+   * @see <a href="http://goo.gl/NhbZ2F">Stackoverflow Basic Authentication</a>
+   *
+   * @throws UnsupportedEncodingException
+   */
+  private String decodeAuthenticationHeader(HttpServletRequest request,
+    String authentication)
+    throws UnsupportedEncodingException
+  {
+
+    String encoding = Objects.firstNonNull(request.getCharacterEncoding(),
+                        DEFAULT_ENCODING);
+
+    String token = authentication.substring(6);
+
+    try
+    {
+      token = new String(Base64.decode(token.getBytes(encoding)));
+    }
+    catch (UnsupportedEncodingException ex)
+    {
+      logger.warn(
+        "encoding {} is not supported, use {} for decoding basic auth",
+        encoding, DEFAULT_ENCODING);
+      token = new String(Base64.decode(token.getBytes(DEFAULT_ENCODING)));
+    }
+
+    return token;
+  }
+
   //~--- fields ---------------------------------------------------------------
 
   /** scm main configuration */