--- OLD/io.c	Thu Jan  1 00:00:00 1970
+++ NEW/io.c	Thu Jan  1 00:00:00 1970
@@ -316,8 +316,8 @@
 		}
 
 		if (remaining > sizeof(line) - 1) {
-			rprintf(FERROR, "multiplexing overflow %d\n\n",
-				remaining);
+			rprintf(FERROR, "multiplexing overflow %lu\n\n",
+				(unsigned long int) remaining);
 			exit_cleanup(RERR_STREAMIO);
 		}