diff --git a/Marlin/src/sd/usb_flashdrive/Sd2Card_FlashDrive.h b/Marlin/src/sd/usb_flashdrive/Sd2Card_FlashDrive.h
index ac6e094147a1..537134fa9ce4 100644
--- a/Marlin/src/sd/usb_flashdrive/Sd2Card_FlashDrive.h
+++ b/Marlin/src/sd/usb_flashdrive/Sd2Card_FlashDrive.h
@@ -49,31 +49,31 @@
 
 class DiskIODriver_USBFlash : public DiskIODriver {
   private:
-    uint32_t pos;
+    static uint32_t pos;
 
-    void usbStateDebug();
+    static void usbStateDebug();
 
   public:
-    bool usbStartup();
+    static bool usbStartup();
 
-    bool init(const uint8_t sckRateID=0, const pin_t chipSelectPin=TERN(USE_OTG_USB_HOST, 0, SD_CHIP_SELECT_PIN));
+    static bool init(const uint8_t sckRateID=0, const pin_t chipSelectPin=TERN(USE_OTG_USB_HOST, 0, SD_CHIP_SELECT_PIN));
 
-    void idle();
+    static void idle();
 
-    inline bool readStart(const uint32_t block)                  { pos = block; return isReady(); }
-    inline bool readData(uint8_t *dst)                           { return readBlock(pos++, dst); }
+    static inline bool readStart(const uint32_t block)                  { pos = block; return isReady(); }
+    static inline bool readData(uint8_t *dst)                           { return readBlock(pos++, dst); }
     //static inline bool readStop()                                     { return true; }
 
-    inline bool writeStart(const uint32_t block, const uint32_t) { pos = block; return isReady(); }
-    inline bool writeData(const uint8_t *src)                    { return writeBlock(pos++, src); }
+    static inline bool writeStart(const uint32_t block, const uint32_t) { pos = block; return isReady(); }
+    static inline bool writeData(const uint8_t *src)                    { return writeBlock(pos++, src); }
     //static inline bool writeStop()                                    { return true; }
 
-    bool readBlock(uint32_t block, uint8_t *dst);
-    bool writeBlock(uint32_t blockNumber, const uint8_t *src);
+    static bool readBlock(uint32_t block, uint8_t *dst);
+    static bool writeBlock(uint32_t blockNumber, const uint8_t *src);
 
     //static bool readCSD(csd_t*)                                       { return true; }
 
-    uint32_t cardSize();
-    bool isInserted();
-    bool isReady();
+    static uint32_t cardSize();
+    static bool isInserted();
+    static bool isReady();
 };