diff --git a/common/usb_cdc.h b/common/usb_cdc.h
index 3b95a11c1..a74e3d8c1 100644
--- a/common/usb_cdc.h
+++ b/common/usb_cdc.h
@@ -41,11 +41,11 @@
 #include "proxmark3.h" // USB_CONNECT()
 #include "common.h"
 
-void usb_disable();
-void usb_enable();
-bool usb_check();
-bool usb_poll();
-bool usb_poll_validate_length();
+void usb_disable(void);
+void usb_enable(void);
+bool usb_check(void);
+bool usb_poll(void);
+bool usb_poll_validate_length(void);
 uint32_t usb_read(uint8_t *data, size_t len);
 uint32_t usb_write(const uint8_t *data, const size_t len);
 
@@ -57,7 +57,7 @@ int GetUSBconfigured(void);
 void AT91F_USB_SendData(AT91PS_UDP pUdp, const char *pData, uint32_t length);
 void AT91F_USB_SendZlp(AT91PS_UDP pUdp);
 void AT91F_USB_SendStall(AT91PS_UDP pUdp);
-void AT91F_CDC_Enumerate();
+void AT91F_CDC_Enumerate(void);
 
 #endif // _USB_CDC_H_
 
diff --git a/include/legic_prng.h b/include/legic_prng.h
index 8f37e04a1..c34455c4c 100644
--- a/include/legic_prng.h
+++ b/include/legic_prng.h
@@ -12,7 +12,7 @@
 #include <stdint.h>
 void legic_prng_init(uint8_t iv);
 void legic_prng_forward(int count);
-uint8_t legic_prng_get_bit();
+uint8_t legic_prng_get_bit(void);
 uint32_t legic_prng_get_bits(uint8_t len);
 #endif