diff --git a/examples/htool.c b/examples/htool.c
index 0a3c758..3e1b02f 100644
--- a/examples/htool.c
+++ b/examples/htool.c
@@ -2038,6 +2038,12 @@ static const struct htool_cmd CMDS[] = {
                          "other output files are not required."},
                 {}},
     },
+    {
+        .verbs = (const char*[]){"security", "startup", NULL},
+        .desc = "Send TPM2_Startup(CLEAR) command to initialize the TPM.",
+        .params = (const struct htool_param[]){{}},
+        .func = htool_security_startup,
+    },
     {
         .verbs = (const char*[]){"mauv", "compiled", NULL},
         .desc = "Get compiled MAUV",
diff --git a/examples/htool_tpm.c b/examples/htool_tpm.c
index ca7f0fa..f4e3a2d 100644
--- a/examples/htool_tpm.c
+++ b/examples/htool_tpm.c
@@ -21,6 +21,7 @@
 #include "host_commands.h"
 #include "htool.h"
 #include "htool_cmd.h"
+#include "htool_security_version.h"
 #include "transports/libhoth_device.h"
 
 int htool_set_tpm_mode(const struct htool_invocation* inv) {
@@ -86,3 +87,43 @@ int htool_get_tpm_mode(const struct htool_invocation* inv) {
 
   return 0;
 }
+
+int htool_security_startup(const struct htool_invocation* inv) {
+  struct libhoth_device* dev = htool_libhoth_device();
+  if (!dev) {
+    return -1;
+  }
+
+  libhoth_security_version sv = htool_get_security_version(dev);
+  switch (sv) {
+    case LIBHOTH_SECURITY_V2: {
+      fprintf(stderr, "security startup is not supported on Security V2\n");
+      return 0;
+    }
+    case LIBHOTH_SECURITY_V3: {
+      // Standard 12-byte TPM2_Startup(CLEAR) command packet
+      static const uint8_t req[12] = {
+          0x80, 0x01,             // TPM_ST_NO_SESSIONS
+          0x00, 0x00, 0x00, 0x0c, // paramSize = 12
+          0x00, 0x00, 0x01, 0x44, // TPM_CC_Startup
+          0x00, 0x00              // TPM_SU_CLEAR
+      };
+
+      uint8_t resp[32];
+      size_t resp_size = 0;
+      int ret = libhoth_hostcmd_exec(
+          dev, HOTH_CMD_BOARD_SPECIFIC_BASE + HOTH_PRV_CMD_HAVEN_TPM, 0, req,
+          sizeof(req), resp, sizeof(resp), &resp_size);
+      if (ret) {
+        htool_report_error("security startup", ret);
+        return ret;
+      }
+
+      printf("TPM2_Startup(CLEAR) sent successfully.\n");
+      return 0;
+    }
+    default: {
+      return -1;
+    }
+  }
+}
diff --git a/examples/htool_tpm.h b/examples/htool_tpm.h
index 6fe0129..a54cb9b 100644
--- a/examples/htool_tpm.h
+++ b/examples/htool_tpm.h
@@ -23,6 +23,7 @@ extern "C" {
 
 #define HOTH_PRV_CMD_SET_TPM_MODE 0x0051
 #define HOTH_PRV_CMD_GET_TPM_MODE 0x0052
+#define HOTH_PRV_CMD_HAVEN_TPM 0x0033
 
 enum ec_tpm_mode {
   TPM_MODE_DISABLED = 0,  // Turn the TPM off: typically used to turn off one
@@ -38,6 +39,7 @@ struct tpm_mode {
 
 int htool_set_tpm_mode(const struct htool_invocation* inv);
 int htool_get_tpm_mode(const struct htool_invocation* inv);
+int htool_security_startup(const struct htool_invocation* inv);
 
 #ifdef __cplusplus
 }