diff --git a/cores/mist/mfp.v b/cores/mist/mfp.v
index 4c4ad98..efffecd 100644
--- a/cores/mist/mfp.v
+++ b/cores/mist/mfp.v
@@ -122,7 +122,7 @@ mfp_timer timer_a (
    .DAT_O		(timera_dat_o),
    .DAT_WE		((addr == 5'h0f) && write),
 	.PULSE_MODE (pulse_mode[1]),
-   .T_I			(t_i[0] ^ aer[4]),
+   .T_I			(t_i[0] ^ ~aer[4]),
    .T_O_PULSE	(timera_done)
 );
 
@@ -141,7 +141,7 @@ mfp_timer timer_b (
    .DAT_O		(timerb_dat_o),
    .DAT_WE		((addr == 5'h10) && write),
 	.PULSE_MODE (pulse_mode[0]),
-   .T_I			(t_i[1] ^ aer[3]),
+   .T_I			(t_i[1] ^ ~aer[3]),
    .T_O_PULSE	(timerb_done)
 );
 
diff --git a/cores/mist/mist_top.v b/cores/mist/mist_top.v
index bac66d9..edc22d5 100644
--- a/cores/mist/mist_top.v
+++ b/cores/mist/mist_top.v
@@ -363,7 +363,7 @@ wire mfp_io0 = (usb_redirection == 2'd2)?parallel_fifo_full:~joy0[4];
 
 // inputs 1,2 and 6 are inputs from serial which have pullups before an inverter
 wire [7:0] mfp_gpio_in = {mfp_io7, 1'b0, !dma_irq, !acia_irq, !blitter_irq, 2'b00, mfp_io0};
-wire [1:0] mfp_timer_in = {st_de, ste?ste_dma_snd_xsirq_delayed:parallel_fifo_full};
+wire [1:0] mfp_timer_in = {!st_de, ste?ste_dma_snd_xsirq_delayed:!parallel_fifo_full};
 
 mfp mfp (
 	// cpu register interface