diff --git a/firmware/target/coldfire/mpio/hd200/adc-hd200.c b/firmware/target/coldfire/mpio/hd200/adc-hd200.c
index 8bf96436bf..8a64e00443 100644
--- a/firmware/target/coldfire/mpio/hd200/adc-hd200.c
+++ b/firmware/target/coldfire/mpio/hd200/adc-hd200.c
@@ -40,7 +40,7 @@ volatile unsigned short adc_data[NUM_ADC_CHANNELS] IBSS_ATTR;
 void ADC(void) __attribute__ ((interrupt_handler,section(".icode")));
 void ADC(void)
 {
-    static unsigned char channel;
+    static unsigned int channel IBSS_ATTR;
     /* read current value */
     adc_data[(channel & 0x03)] = ADVALUE;