diff --git a/src/preferences/preferences.cpp b/src/preferences/preferences.cpp
index 4eeffa0ab..22ca38016 100644
--- a/src/preferences/preferences.cpp
+++ b/src/preferences/preferences.cpp
@@ -1394,7 +1394,7 @@ QString getRegValue(HKEY handle, const QString &name = QString())
         delete[] lpValueName;
 
     if (res == ERROR_SUCCESS) {
-        lpData[cBuffer] = 0;
+        lpData[cBuffer - 1] = 0;
         result = QString::fromWCharArray(lpData);
     }
     delete[] lpData;