diff --git a/Source/CursesDialog/form/fty_alpha.c b/Source/CursesDialog/form/fty_alpha.c
index 8f41de11c..e4e9ceb1c 100644
--- a/Source/CursesDialog/form/fty_alpha.c
+++ b/Source/CursesDialog/form/fty_alpha.c
@@ -116,6 +116,7 @@ static bool Check_Alpha_Field(FIELD * field, const void * argp)
 +--------------------------------------------------------------------------*/
 static bool Check_Alpha_Character(int c, const void * argp)
 {
+  argp=0; /* Silence unused parameter warning.  */
   return (isalpha(c) ? TRUE : FALSE);
 }