diff --git a/src/engine/engine.cpp b/src/engine/engine.cpp
index 153923c0c..86dcfb5ff 100644
--- a/src/engine/engine.cpp
+++ b/src/engine/engine.cpp
@@ -1067,6 +1067,10 @@ bool DivEngine::setSystemChans(int index, int ch, bool preserveOrder) {
     lastError=_("invalid index");
     return false;
   }
+  if (ch<1) {
+    lastError=_("channel count should be at least 1");
+    return false;
+  }
   if (song.chans-song.systemChans[index]+ch>DIV_MAX_CHANS) {
     lastError=fmt::sprintf(_("max number of total channels is %d"),DIV_MAX_CHANS);
     return false;
diff --git a/src/gui/sysConf.cpp b/src/gui/sysConf.cpp
index 69b90c701..3348d2d02 100644
--- a/src/gui/sysConf.cpp
+++ b/src/gui/sysConf.cpp
@@ -2797,7 +2797,7 @@ bool FurnaceGUI::drawSysConf(int chan, int sysPos, DivSystem type, DivConfig& fl
         updateWindowTitle();
         updateROMExportAvail();
       } else {
-        showError(fmt::sprintf(_("cannot change chip! (%s)"),e->getLastError()));
+        showError(e->getLastError());
       }
     }
     if (sysDef!=NULL) {