diff --git a/lib/krb5/prog_setup.c b/lib/krb5/prog_setup.c
index 1e83b4d06..21afbf8d1 100644
--- a/lib/krb5/prog_setup.c
+++ b/lib/krb5/prog_setup.c
@@ -45,7 +45,7 @@ krb5_std_usage(int code, struct getargs *args, int num_args)
 KRB5_LIB_FUNCTION int KRB5_LIB_CALL
 krb5_program_setup(krb5_context *context, int argc, char **argv,
 		   struct getargs *args, int num_args,
-		   void (*usage)(int, struct getargs*, int))
+		   void (KRB5_LIB_CALL *usage)(int, struct getargs*, int))
 {
     krb5_error_code ret;
     int optidx = 0;