diff --git a/golded3/geutil.cpp b/golded3/geutil.cpp
index 27a6301..3c7d239 100644
--- a/golded3/geutil.cpp
+++ b/golded3/geutil.cpp
@@ -145,6 +145,14 @@ void update_statusline(const char* info) {
 
 void update_statuslinef(const char *format, const char *token, ...)
 {
+  if ( !(format && *format && token && *token) )
+  {
+    LOG.errpointer(__FILE__, __LINE__);
+    LOG.printf( "! Parameter is NULL pointer or empty string: update_statuslinef(%s,%s,...).",
+                (format?(*format)?"format":"\"\"":"NULL"), (token?(*token)?"token":"\"\"":"NULL") );
+    return;
+  }
+
   bool error = false;
   char winfobuf[350];
   va_list argptr;