diff --git a/man/scdtotp.1.in b/man/scdtotp.1.in
index a2ac171..94657bf 100644
--- a/man/scdtotp.1.in
+++ b/man/scdtotp.1.in
@@ -15,6 +15,8 @@ scdtotp \- Generate one-time passwords from an OpenPGP smartcard
 .IR N ]
 .RB [ \-m | --mac-algo
 .IR algo ]
+.RB [ \-n | --private-do
+.IR N ]
 .YS
 
 .SH DESCRIPTION
@@ -52,6 +54,10 @@ digits.
 .BR -m ", " --mac-algo " " \fialgo\fR
 Select the HMAC algorithm to use among
 \fisha1\fR (default), \fisha256\fR, or \fisha512\fR.
+.TP
+.BR -n ", " --private-do " " \fiN\fR
+Read key from private DO slot #\fiN\fR
+(default is 1).
 
 .SH REPORTING BUGS
 .PP
diff --git a/src/scdtotp.c b/src/scdtotp.c
index 1490454..8b574f1 100644
--- a/src/scdtotp.c
+++ b/src/scdtotp.c
@@ -35,6 +35,7 @@
 #define DEFAULT_TIME_STEP   30
 #define DEFAULT_DIGITS      6
 #define MAX_KEY_SIZE        64
+#define DEFAULT_PRIVATE_DO  1
 
 static void
 usage(int status)
@@ -64,6 +65,11 @@ found in a OpenPGP smartcard.\n\
                         'sha256' or 'sha512'.\n\
 ");
 
+    printf("\n\
+  -n, --private-do N    Read key from private data object N\n\
+                        (default is %d).\n\
+", DEFAULT_PRIVATE_DO);
+
     printf("Report bugs to <%s>.\n", PACKAGE_BUGREPORT);
 
     exit(status);
@@ -262,7 +268,7 @@ get_otp_key_cb(void *arg, const char *line)
 {
     struct key_data_t *key = (struct key_data_t *)arg;
 
-    if ( ! strncmp("PRIVATE-DO-1", line, 12) ) {
+    if ( ! strncmp("PRIVATE-DO-", line, 11) ) {
         const char *cursor;
         size_t n;
 
@@ -291,19 +297,25 @@ get_otp_key_cb(void *arg, const char *line)
  * @return 0 if successful, or a gpg_error_t error code.
  */
 static gpg_error_t
-get_otp_key(unsigned char *buffer, size_t len)
+get_otp_key(unsigned privatedo, unsigned char *buffer, size_t len)
 {
     assuan_context_t ctx;
     gpg_error_t e;
     struct key_data_t key;
+    char command[32];
 
     key.buffer = buffer;
     key.len = len;
     key.found = 0;
 
+    if ( privatedo < 1 || privatedo > 4 )
+        return gcry_error(GPG_ERR_INV_ARG);
+
     if ( ! (e = connect_to_scdaemon(&ctx)) ) {
 
-        if ( ! (e = assuan_transact(ctx, "GETATTR PRIVATE-DO-1", NULL, NULL,
+        snprintf(command, sizeof(command), "GETATTR PRIVATE-DO-%d", privatedo);
+
+        if ( ! (e = assuan_transact(ctx, command, NULL, NULL,
                         NULL, NULL, get_otp_key_cb, &key)) ) {
             if ( key.found )
                 e = gcry_error(GPG_ERR_NO_ERROR);
@@ -345,7 +357,7 @@ main(int argc, char **argv)
 {
     int c, algo;
     unsigned char key[MAX_KEY_SIZE * 2 + 1];
-    unsigned otp, step, digits;
+    unsigned otp, step, digits, privatedo;
     time_t secs;
     gcry_error_t e;
 
@@ -356,6 +368,7 @@ main(int argc, char **argv)
         { "step",       1, NULL, 's' },
         { "digits",     1, NULL, 'd' },
         { "mac-algo",   1, NULL, 'm' },
+        { "private-do", 1, NULL, 'n' },
         { NULL,         0, NULL, 0 }
     };
 
@@ -364,8 +377,9 @@ main(int argc, char **argv)
     step = DEFAULT_TIME_STEP;
     digits = DEFAULT_DIGITS;
     algo = GCRY_MAC_HMAC_SHA1;
+    privatedo = DEFAULT_PRIVATE_DO;
 
-    while ( (c = getopt_long(argc, argv, "hvt:s:d:m:",
+    while ( (c = getopt_long(argc, argv, "hvt:s:d:m:n:",
                              options, NULL)) != -1 ) {
         switch ( c ) {
         case 'h':
@@ -404,6 +418,12 @@ main(int argc, char **argv)
             else
                 errx(EXIT_FAILURE, "unsupported HMAC algorithm: %s", optarg);
             break;
+
+        case 'n':
+            privatedo = get_uinteger_or_die(optarg);
+            if ( privatedo < 1 || privatedo > 4 )
+                errx(EXIT_FAILURE, "DO number must be 1, 2, 3, or 4");
+            break;
         }
     }
 
@@ -413,7 +433,7 @@ main(int argc, char **argv)
     gcry_control(GCRYCTL_DISABLE_SECMEM, 0);
     gcry_control(GCRYCTL_INITIALIZATION_FINISHED, 0);
 
-    if ( (e = get_otp_key(key, sizeof(key))) )
+    if ( (e = get_otp_key(privatedo, key, sizeof(key))) )
         errx(EXIT_FAILURE, "Cannot get key from token: %s", gcry_strerror(e));
 
     if ( (e = generate_totp(algo, key, secs, step, digits, &otp)) )