diff --git a/stm-firmware/adc-meas.c b/stm-firmware/adc-meas.c
index ba0b8c0..0438728 100644
--- a/stm-firmware/adc-meas.c
+++ b/stm-firmware/adc-meas.c
@@ -263,7 +263,7 @@ static inline __attribute__((optimize("O3"))) float adc_pt1000_dma_avg_pre_filte
 	sum = sum - (uint32_t)max_val - (uint32_t)min_val;
 
 	/* Divide to get average and return */
-	return (float)(sum / (ADC_PT1000_DMA_AVG_SAMPLES-2));
+	return (float)sum / (float)(ADC_PT1000_DMA_AVG_SAMPLES-2);
 }
 
 void ADC_IRQHandler(void)