diff --git a/pic/MDR/MDR.c b/pic/MDR/MDR.c
index 0b648e4..259ef08 100644
--- a/pic/MDR/MDR.c
+++ b/pic/MDR/MDR.c
@@ -362,10 +362,12 @@ static void interrupt(void) __interrupt 0
 		} else {
 			led_on();
 		}
-		/* pressed for 5s, clear memory */
+		/* button pressed for 5s, clear memory */
 		if (hold==20) {
 			led_on();
-			clear_memory();
+			if (!(PORTB&SWITCH1)) { /* ensure the button is pressed */
+				clear_memory();
+			}
 			led_off();
 			TMR4ON = 0;
 		}