diff --git a/sys/boot/arm/at91/libat91/getc.c b/sys/boot/arm/at91/libat91/getc.c
index c86183b4dc5d..e0a43b9b9a65 100644
--- a/sys/boot/arm/at91/libat91/getc.c
+++ b/sys/boot/arm/at91/libat91/getc.c
@@ -53,10 +53,10 @@ getc(int seconds)
 	thisSecond = GetSeconds();
 	seconds = thisSecond + seconds;
 
-	while (thisSecond <= seconds) {
+	do {
 		if ((pUSART->US_CSR & AT91C_US_RXRDY))
 			return (pUSART->US_RHR & 0xFF);
 		thisSecond = GetSeconds();
-	}
+	} while (thisSecond < seconds);
 	return (-1);
 }