diff --git a/cgpt/cgpt_boot.c b/cgpt/cgpt_boot.c
index 386c4f4..993e865 100644
--- a/cgpt/cgpt_boot.c
+++ b/cgpt/cgpt_boot.c
@@ -78,6 +78,15 @@
     return CGPT_FAILED;
   }
 
+  if (drive.is_mtd) {
+    /* This command manipulates the legacy MBR sector present at the beginning
+     * of the GPT structures, and so doesn't apply to MTD drives.
+     */
+    Error("'boot' command unsupported in MTD mode\n");
+    retval = CGPT_FAILED;
+    goto done;
+  }
+
   if (CGPT_OK != ReadPMBR(&drive)) {
     Error("Unable to read PMBR\n");
     goto done;
diff --git a/cgpt/cgpt_legacy.c b/cgpt/cgpt_legacy.c
index 932fbb9..e736bd4 100644
--- a/cgpt/cgpt_legacy.c
+++ b/cgpt/cgpt_legacy.c
@@ -18,6 +18,13 @@
   if (CGPT_OK != DriveOpen(params->drive_name, &drive, O_RDWR))
     return CGPT_FAILED;
 
+  if (drive.is_mtd) {
+    // This command requires GPT mode.
+    Error("'legacy' command unsupported in MTD mode\n");
+    DriveClose(&drive, 0);
+    return CGPT_FAILED;
+  }
+
   h1 = (GptHeader *)drive.gpt.primary_header;
   h2 = (GptHeader *)drive.gpt.secondary_header;
   if (params->efipart) {
diff --git a/cgpt/cgpt_repair.c b/cgpt/cgpt_repair.c
index e591c75..9b4d2df 100644
--- a/cgpt/cgpt_repair.c
+++ b/cgpt/cgpt_repair.c
@@ -18,6 +18,12 @@
   if (CGPT_OK != DriveOpen(params->drive_name, &drive, O_RDWR))
     return CGPT_FAILED;
 
+  if (drive.is_mtd) {
+    // Nothing to do
+    DriveClose(&drive, 0);
+    return 0;
+  }
+
   int gpt_retval = GptSanityCheck(&drive.gpt);
   if (params->verbose)
     printf("GptSanityCheck() returned %d: %s\n",