diff --git a/dediprog.c b/dediprog.c
index 8029b64..5af1eec 100644
--- a/dediprog.c
+++ b/dediprog.c
@@ -43,7 +43,7 @@
 #define REQTYPE_OTHER_IN (LIBUSB_ENDPOINT_IN | LIBUSB_REQUEST_TYPE_VENDOR | LIBUSB_RECIPIENT_OTHER)	/* 0xC3 */
 #define REQTYPE_EP_OUT (LIBUSB_ENDPOINT_OUT | LIBUSB_REQUEST_TYPE_VENDOR | LIBUSB_RECIPIENT_ENDPOINT)	/* 0x42 */
 #define REQTYPE_EP_IN (LIBUSB_ENDPOINT_IN | LIBUSB_REQUEST_TYPE_VENDOR | LIBUSB_RECIPIENT_ENDPOINT)	/* 0xC2 */
-struct libusb_context *usb_ctx;
+static struct libusb_context *usb_ctx;
 static libusb_device_handle *dediprog_handle;
 static int dediprog_in_endpoint;
 static int dediprog_out_endpoint;
@@ -159,7 +159,7 @@
 };
 
 static int dediprog_firmwareversion = FIRMWARE_VERSION(0, 0, 0);
-enum dediprog_devtype dediprog_devicetype = DEV_UNKNOWN;
+static enum dediprog_devtype dediprog_devicetype = DEV_UNKNOWN;
 
 #if defined(LIBUSB_MAJOR) && defined(LIBUSB_MINOR) && defined(LIBUSB_MICRO) && \
     LIBUSB_MAJOR <= 1 && LIBUSB_MINOR == 0 && LIBUSB_MICRO < 9