diff --git a/gerrit-httpd/src/main/java/com/google/gerrit/httpd/auth/container/HttpAuthFilter.java b/gerrit-httpd/src/main/java/com/google/gerrit/httpd/auth/container/HttpAuthFilter.java
index 5bad3f74b3..978f0814e1 100644
--- a/gerrit-httpd/src/main/java/com/google/gerrit/httpd/auth/container/HttpAuthFilter.java
+++ b/gerrit-httpd/src/main/java/com/google/gerrit/httpd/auth/container/HttpAuthFilter.java
@@ -18,6 +18,8 @@ import static com.google.common.base.MoreObjects.firstNonNull;
 import static com.google.common.base.Strings.emptyToNull;
 import static com.google.common.net.HttpHeaders.AUTHORIZATION;
 import static com.google.gerrit.reviewdb.client.AccountExternalId.SCHEME_GERRIT;
+import static java.nio.charset.StandardCharsets.ISO_8859_1;
+import static java.nio.charset.StandardCharsets.UTF_8;
 
 import com.google.gerrit.extensions.registration.DynamicItem;
 import com.google.gerrit.httpd.HtmlDomUtil;
@@ -143,7 +145,8 @@ class HttpAuthFilter implements Filter {
 
   String getRemoteDisplayname(HttpServletRequest req) {
     if (displaynameHeader != null) {
-      return emptyToNull(req.getHeader(displaynameHeader));
+      String raw = req.getHeader(displaynameHeader);
+      return emptyToNull(new String(raw.getBytes(ISO_8859_1), UTF_8));
     }
     return null;
   }