diff --git a/src/engine/engine.cpp b/src/engine/engine.cpp
index b2a4b4428..c062d22c8 100644
--- a/src/engine/engine.cpp
+++ b/src/engine/engine.cpp
@@ -562,6 +562,9 @@ void DivEngine::initSongWithDesc(const char* description, bool inBase64, bool ol
   
   // extra attributes
   song.subsong[0]->hz=c.getDouble("tickRate",60.0);
+  if (song.subsong[0]->hz<1.0) song->subsong[0]->hz=1.0;
+  if (song.subsong[0]->hz>999.0) song->subsong[0]->hz=999.0;
+
   song.author=getConfString("defaultAuthorName","");
 }