diff --git a/src/base/digest32.h b/src/base/digest32.h
index b187f3bb4..ffbee3043 100644
--- a/src/base/digest32.h
+++ b/src/base/digest32.h
@@ -122,7 +122,7 @@ public:
 
     QString hashString() const
     {
-        if (m_hashString.isEmpty())
+        if (m_hashString.isEmpty() && isValid())
         {
             const QByteArray raw = QByteArray::fromRawData(m_nativeDigest.data(), length());
             m_hashString = QString::fromLatin1(raw.toHex());