diff --git a/src/debug.c b/src/debug.c
index df8951ec0..de66c0879 100644
--- a/src/debug.c
+++ b/src/debug.c
@@ -199,7 +199,7 @@ void HAMLIB_API rig_set_debug_time_stamp(int flag)
  * \param debug_level Debug level from none to most output.
  * \param fmt Formatted character string to print.
  *
- * The formatted character string is passed to the `frprintf`(3) C library
+ * The formatted character string is passed to the `vfprintf`(3) C library
  * call and follows its format specification.
  */
 #undef rig_debug