diff --git a/sbin/md5/md5.c b/sbin/md5/md5.c
--- a/sbin/md5/md5.c
+++ b/sbin/md5/md5.c
@@ -158,6 +158,45 @@
 	MD5Update(c, data, len);
 }
 
+struct chksumrec {
+	char	*filename;
+	char	*chksum;
+	struct chksumrec	*next;
+};
+
+static struct chksumrec *head;
+
+static int gnu_check(const char *checksumsfile)
+{
+	FILE	*inp;
+	char	sum[257];	/* 1024 bit hash as hex number string */
+	char	file[1025];	/* MAXPATHLEN + 1 to allow for leading '*' */
+	int	lineno;
+	struct chksumrec	*rec;
+
+	if ((inp = fopen(checksumsfile, "r")) == NULL)
+		err(3, "%s", checksumsfile);
+	head = NULL;
+	lineno = 1;
+	while (!feof(inp)) {
+		if (fscanf(inp, "%256s %1024s\n", sum, file) != 2) {
+			errx(3, "malformed input line %d", lineno);
+		}
+		rec = malloc(sizeof (*rec));
+		if (rec == NULL)
+			errx(1, "malloc failed");
+		rec->chksum = strdup(sum);
+		rec->filename = strdup(*file == '*' ? file + 1 : file);
+		if (rec->chksum == NULL || rec->filename == NULL)
+			errx(1, "malloc failed");
+		rec->next = head;
+		head = rec;
+		lineno++;
+	}
+	fclose(inp);
+	return (lineno - 1);
+}
+
 /* Main driver.
 
 Arguments (may be any combination):
@@ -180,6 +219,8 @@
  	unsigned	digest;
 	char	*progname;
 	bool	gnu_emu = false;
+	struct chksumrec	*rec;
+	int	numrecs;
 
  	if ((progname = strrchr(argv[0], '/')) == NULL)
  		progname = argv[0];
@@ -221,8 +262,9 @@
 			break;
 		case 'c':
 			if (gnu_emu)
-				errx(1, "-c check option not supported");
-			checkAgainst = optarg;
+				numrecs = gnu_check(optarg);
+			else
+				checkAgainst = optarg;
 			break;
 		case 'p':
 			pflag = 1;
@@ -258,6 +300,16 @@
 		err(1, "unable to limit rights for stdio");
 #endif
 
+	if (gnu_emu) {
+		argc = 0;
+		argv = (char**)calloc(sizeof(char *), numrecs + 1);
+		for (rec = head; rec != NULL; rec = rec->next) {
+			argv[argc] = rec->filename;
+			argc++;
+		}
+		rec = head;
+	}
+
 	if (*argv) {
 		do {
 			if ((fd = open(*argv, O_RDONLY)) < 0) {
@@ -279,6 +331,10 @@
 					err(1, "capsicum");
 #endif
 			}
+			if (gnu_emu) {
+				checkAgainst = rec->chksum;
+				rec = rec->next;
+			}
 			p = Algorithm[digest].Fd(fd, buf);
 			(void)close(fd);
 			MDOutput(&Algorithm[digest], p, argv);