diff --git a/main.c b/main.c
index c1d50ea..c8ea9b7 100644
--- a/main.c
+++ b/main.c
@@ -34,7 +34,7 @@ static int setpassword(const char *password)
         }
     }
     printf("Updating password to `%s'... ", password);
-    if (send_command(ACTIONPRO_OPCODE_SETPASSWORD, password, slen) == ACTIONPRO_CMD_OK)
+    if (send_command(ACTIONPRO_OPCODE_SETPASSWORD, (const uint8_t *)password, slen) == ACTIONPRO_CMD_OK)
         printf("OK\n");
     else
         printf("ERROR\n");
@@ -61,7 +61,7 @@ static int setssid(const char *ssid)
         }
     }
     printf("Updating SSID to `%s'... ", ssid);
-    if (send_command(ACTIONPRO_OPCODE_SETSSID, ssid, slen) == ACTIONPRO_CMD_OK)
+    if (send_command(ACTIONPRO_OPCODE_SETSSID, (const uint8_t *)ssid, slen) == ACTIONPRO_CMD_OK)
         printf("OK\n");
     else
         printf("ERROR\n");
diff --git a/usbms.c b/usbms.c
index 5a8049c..3eeaf60 100644
--- a/usbms.c
+++ b/usbms.c
@@ -34,7 +34,7 @@
 
 static struct libusb_device_handle *handle = NULL;
 
-int send_command(const uint8_t opcode, const char *buf, const uint8_t buflen)
+int send_command(const uint8_t opcode, const uint8_t *buf, const uint8_t buflen)
 {
     int rc;
     uint32_t expected_tag = 0;
diff --git a/usbms.h b/usbms.h
index 7e2abfa..2b780cb 100644
--- a/usbms.h
+++ b/usbms.h
@@ -27,6 +27,6 @@
 /* exported functions */
 extern int open_device();
 extern int close_device();
-extern int send_command(const uint8_t opcode, const char *buf, const uint8_t buflen);
+extern int send_command(const uint8_t opcode, const uint8_t *buf, const uint8_t buflen);
 
 #endif /* usbms_h */