diff --git a/src/sbbs3/smbutil.c b/src/sbbs3/smbutil.c
index bd2cdc14b117ec8679033a617b1f4038db259ab4..1dda0a3d0dbcde0f984eea4dba9c4d6a4072dd36 100644
--- a/src/sbbs3/smbutil.c
+++ b/src/sbbs3/smbutil.c
@@ -678,7 +678,7 @@ void maint(void)
 	if((idx=(idxrec_t *)malloc(sizeof(idxrec_t)*smb.status.total_msgs))
 		==NULL) {
 		smb_unlocksmbhdr(&smb);
-		fprintf(errfp,"\n%s!Error allocating %u bytes of memory\n"
+		fprintf(errfp,"\n%s!Error allocating %" XP_PRIsize_t "u bytes of memory\n"
 			,beep,sizeof(idxrec_t)*smb.status.total_msgs);
 		return; 
 	}