diff --git a/tools/assistant/tools/assistant/helpviewer.cpp b/tools/assistant/to
ols/assistant/helpviewer.cpp
index 7783247..509a132 100644
--- a/tools/assistant/tools/assistant/helpviewer.cpp
+++ b/tools/assistant/tools/assistant/helpviewer.cpp
@@ -147,7 +147,11 @@ QNetworkReply *HelpNetworkAccessManager::createRequest(Oper
ation /*op*/,
     }
     else if (mimeType.endsWith(QLatin1String(".js"))) {
         mimeType = QLatin1String("text/javascript");
-    } else {
+    }
+    else if (mimeType.endsWith(QLatin1String(".png"))) {
+        mimeType = QLatin1String("image/png");
+    }
+    else {
         mimeType = QLatin1String("text/html");
     }