diff --git a/armsrc/lfops.c b/armsrc/lfops.c
index c80700aea..642b19377 100644
--- a/armsrc/lfops.c
+++ b/armsrc/lfops.c
@@ -393,6 +393,8 @@ void SimulateTagLowFrequency(int period, int gap, int ledcontrol)
 	int i = 0;
 	uint8_t *tab = BigBuf_get_addr();
 
+	StartTicks();
+
 	FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_EDGE_DETECT | FPGA_LF_EDGE_DETECT_READER_FIELD);
 
 	AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DOUT | GPIO_SSC_CLK;