diff --git a/src/open9x.h b/src/open9x.h
index 6efa803d6..c02ede732 100644
--- a/src/open9x.h
+++ b/src/open9x.h
@@ -302,10 +302,10 @@ inline uint8_t KEYS_PRESSED()
 #define INP_G_RuddDR   0
 
 #define KEYS_PRESSED() (~PINB)
-#define DBLKEYS_PRESSED_RGT_LFT(i) (in & ((1<<INP_B_KEY_RGT) + (1<<INP_B_KEY_LFT)))
-#define DBLKEYS_PRESSED_UP_DWN(i)  (in & ((1<<INP_B_KEY_UP) + (1<<INP_B_KEY_DWN)))
-#define DBLKEYS_PRESSED_RGT_UP(i)  (in & ((1<<INP_B_KEY_RGT) + (1<<INP_B_KEY_UP)))
-#define DBLKEYS_PRESSED_LFT_DWN(i) (in & ((1<<INP_B_KEY_LFT) + (1<<INP_B_KEY_DWN)))
+#define DBLKEYS_PRESSED_RGT_LFT(i) ((in & ((1<<INP_B_KEY_RGT) + (1<<INP_B_KEY_LFT))) == ((1<<INP_B_KEY_RGT) + (1<<INP_B_KEY_LFT)))
+#define DBLKEYS_PRESSED_UP_DWN(i)  ((in & ((1<<INP_B_KEY_UP) + (1<<INP_B_KEY_DWN))) == ((1<<INP_B_KEY_UP) + (1<<INP_B_KEY_DWN)))
+#define DBLKEYS_PRESSED_RGT_UP(i)  ((in & ((1<<INP_B_KEY_RGT) + (1<<INP_B_KEY_UP))) == ((1<<INP_B_KEY_RGT) + (1<<INP_B_KEY_UP)))
+#define DBLKEYS_PRESSED_LFT_DWN(i) ((in & ((1<<INP_B_KEY_LFT) + (1<<INP_B_KEY_DWN))) == ((1<<INP_B_KEY_LFT) + (1<<INP_B_KEY_DWN)))
 
 #endif // defined (PCBV4)