diff --git a/src/webui/webapplication.cpp b/src/webui/webapplication.cpp
index 709abd481..4ca16c11f 100644
--- a/src/webui/webapplication.cpp
+++ b/src/webui/webapplication.cpp
@@ -191,7 +191,7 @@ void WebApplication::sendWebUIFile()
     sendFile(localPath);
 }
 
-void WebApplication::translateDocument(QString &data)
+void WebApplication::translateDocument(QString &data) const
 {
     const QRegularExpression regex("QBT_TR\\((([^\\)]|\\)(?!QBT_TR))+)\\)QBT_TR\\[CONTEXT=([a-zA-Z_][a-zA-Z0-9_]*)\\]");
 
@@ -368,11 +368,10 @@ void WebApplication::sendFile(const QString &path)
     const QDateTime lastModified {QFileInfo(path).lastModified()};
 
     // find translated file in cache
-    auto it = m_translatedFiles.constFind(path);
-    if ((it != m_translatedFiles.constEnd()) && (lastModified <= (*it).lastModified)) {
-        const QString mimeName {QMimeDatabase().mimeTypeForFileNameAndData(path, (*it).data).name()};
-        print((*it).data, mimeName);
-        header(Http::HEADER_CACHE_CONTROL, getCachingInterval(mimeName));
+    const auto it = m_translatedFiles.constFind(path);
+    if ((it != m_translatedFiles.constEnd()) && (lastModified <= it->lastModified)) {
+        print(it->data, it->mimeType);
+        header(Http::HEADER_CACHE_CONTROL, getCachingInterval(it->mimeType));
         return;
     }
 
@@ -400,7 +399,7 @@ void WebApplication::sendFile(const QString &path)
         translateDocument(dataStr);
         data = dataStr.toUtf8();
 
-        m_translatedFiles[path] = {data, lastModified}; // caching translated file
+        m_translatedFiles[path] = {data, mimeType.name(), lastModified}; // caching translated file
     }
 
     print(data, mimeType.name());
diff --git a/src/webui/webapplication.h b/src/webui/webapplication.h
index 435c5fcb1..43b74d80c 100644
--- a/src/webui/webapplication.h
+++ b/src/webui/webapplication.h
@@ -105,7 +105,7 @@ private:
     void sendFile(const QString &path);
     void sendWebUIFile();
 
-    void translateDocument(QString &data);
+    void translateDocument(QString &data) const;
 
     // Session management
     QString generateSid() const;
@@ -136,6 +136,7 @@ private:
     struct TranslatedFile
     {
         QByteArray data;
+        QString mimeType;
         QDateTime lastModified;
     };
     QHash<QString, TranslatedFile> m_translatedFiles;