diff --git a/src/simpgmspace.h b/src/simpgmspace.h
index f2d045012..4d3ea703a 100644
--- a/src/simpgmspace.h
+++ b/src/simpgmspace.h
@@ -362,6 +362,7 @@ inline void GPIO_Init(GPIO_TypeDef* GPIOx, GPIO_InitTypeDef* GPIO_InitStruct) {
 #define GPIO_ResetBits(GPIOx, pin) GPIOx->BSRRL &= ~pin
 #define GPIO_IsSet(GPIOx, pin) (GPIOx->BSRRL & pin)
 #define RCC_AHB1PeriphClockCmd(...)
+#define GPIO_ReadInputDataBit(...) true
 #endif
 
 #define configure_pins(...)