diff --git a/usr.bin/lam/lam.c b/usr.bin/lam/lam.c
index 68cb4b94657..2194ae7ab59 100644
--- a/usr.bin/lam/lam.c
+++ b/usr.bin/lam/lam.c
@@ -43,6 +43,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sysexits.h>
 #include <unistd.h>
 
 #define	MAXOFILES	20
@@ -212,6 +213,9 @@ gatherline(struct openfile *ip)
 	*p = '\0';
 	if (c == EOF) {
 		ip->eof = 1;
+		if (ferror(ip->fp)) {
+			err(EX_IOERR, NULL);
+		}
 		if (ip->fp == stdin)
 			fclose(stdin);
 		morefiles--;