diff --git a/board/daisy/board.h b/board/daisy/board.h
index da85579d7d..3194a2de70 100644
--- a/board/daisy/board.h
+++ b/board/daisy/board.h
@@ -35,7 +35,8 @@
 
 #define USB_CHARGE_PORT_COUNT 0
 
-/* EC drives 13 outputs to keyboard matrix */
+/* EC drives 13 outputs to the keyboard matrix and reads 8 inputs/interrupts */
+#define KB_INPUTS 8
 #define KB_OUTPUTS 13
 
 /* Charging */
diff --git a/board/snow/board.h b/board/snow/board.h
index 072b5ec40e..27837b665a 100644
--- a/board/snow/board.h
+++ b/board/snow/board.h
@@ -38,7 +38,8 @@
 
 #define USB_CHARGE_PORT_COUNT 0
 
-/* EC drives 13 outputs to keyboard matrix */
+/* EC drives 13 outputs to the keyboard matrix and reads 8 inputs/interrupts */
+#define KB_INPUTS 8
 #define KB_OUTPUTS 13
 
 /* Charging */
diff --git a/board/spring/board.h b/board/spring/board.h
index 836e175e5a..cc1b675141 100644
--- a/board/spring/board.h
+++ b/board/spring/board.h
@@ -41,7 +41,8 @@
 /* By default, enable all console messages except keyboard */
 #define CC_DEFAULT	(CC_ALL & ~CC_MASK(CC_KEYSCAN))
 
-/* EC drives 13 outputs to keyboard matrix */
+/* EC drives 13 outputs to the keyboard matrix and reads 8 inputs/interrupts */
+#define KB_INPUTS 8
 #define KB_OUTPUTS 13
 
 /* Charging */
diff --git a/chip/stm32/keyboard_scan.c b/chip/stm32/keyboard_scan.c
index 9b9b4f0bc0..8fc92edfb8 100644
--- a/chip/stm32/keyboard_scan.c
+++ b/chip/stm32/keyboard_scan.c
@@ -32,8 +32,6 @@ enum {
 	/* 0 ~ 12 for the corresponding output */
 };
 
-#define KB_INPUTS 8
-
 /* Mask of external interrupts on input lines */
 static unsigned int irq_mask;