diff --git a/nanovna.h b/nanovna.h
index 7c61245..ef293f9 100644
--- a/nanovna.h
+++ b/nanovna.h
@@ -210,6 +210,8 @@ float groupdelay_from_array(int i, float array[101][2]);
 
 // marker
 
+#define MARKERS_MAX 4
+
 typedef struct {
   int8_t enabled;
   int16_t index;
@@ -300,7 +302,7 @@ typedef struct {
   float _electrical_delay; // picoseconds
   
   trace_t _trace[TRACES_MAX];
-  marker_t _markers[4];
+  marker_t _markers[MARKERS_MAX];
   int _active_marker;
   uint8_t _domain_mode; /* 0bxxxxxffm : where ff: TD_FUNC m: DOMAIN_MODE */
   uint8_t _velocity_factor; // %
diff --git a/plot.c b/plot.c
index c28f37e..400f0b7 100644
--- a/plot.c
+++ b/plot.c
@@ -1191,7 +1191,7 @@ cell_draw_markers(int m, int n, int w, int h)
   int x0 = m * CELLWIDTH;
   int y0 = n * CELLHEIGHT;
   int t, i;
-  for (i = 0; i < 4; i++) {
+  for (i = 0; i < MARKERS_MAX; i++) {
     if (!markers[i].enabled)
       continue;
     for (t = 0; t < TRACES_MAX; t++) {
@@ -1239,7 +1239,7 @@ void
 markmap_all_markers(void)
 {
   int i;
-  for (i = 0; i < 4; i++) {
+  for (i = 0; i < MARKERS_MAX; i++) {
     if (!markers[i].enabled)
       continue;
     markmap_marker(i);
@@ -1493,24 +1493,48 @@ cell_draw_marker_info(int m, int n, int w, int h)
     return;
   int idx = markers[active_marker].index;
   int j = 0;
-  for (t = 0; t < TRACES_MAX; t++) {
-    if (!trace[t].enabled)
-      continue;
-    int xpos = 1 + (j%2)*146;
-    int ypos = 1 + (j/2)*7;
-    xpos -= m * CELLWIDTH -CELLOFFSETX;
-    ypos -= n * CELLHEIGHT;
-    chsnprintf(buf, sizeof buf, "CH%d", trace[t].channel);
-    cell_drawstring_invert_5x7(w, h, buf, xpos, ypos, config.trace_color[t], t == uistat.current_trace);
-    xpos += 20;
-    trace_get_info(t, buf, sizeof buf);
-    cell_drawstring_5x7(w, h, buf, xpos, ypos, config.trace_color[t]);
-    xpos += 64;
-    trace_get_value_string(t, buf, sizeof buf, measured[trace[t].channel], idx);
-    cell_drawstring_5x7(w, h, buf, xpos, ypos, config.trace_color[t]);
-    j++;
-  }    
-
+  if (active_marker != -1 && previous_marker != -1 && uistat.current_trace != -1) {
+    int t = uistat.current_trace;
+    int mk;
+    for (mk = 0; mk < MARKERS_MAX; mk++) {
+      if (!markers[mk].enabled)
+        continue;
+      int xpos = 1 + (j%2)*146;
+      int ypos = 1 + (j/2)*7;
+      xpos -= m * CELLWIDTH -CELLOFFSETX;
+      ypos -= n * CELLHEIGHT;
+      strcpy(buf, "MK1");
+      buf[2] += mk;
+      cell_drawstring_invert_5x7(w, h, buf, xpos, ypos, config.trace_color[t], mk == active_marker);
+      xpos += 20;
+      trace_get_info(t, buf, sizeof buf);
+      cell_drawstring_5x7(w, h, buf, xpos, ypos, config.trace_color[t]);
+      xpos += 64;
+      trace_get_value_string(t, buf, sizeof buf, measured[trace[t].channel], markers[mk].index);
+      cell_drawstring_5x7(w, h, buf, xpos, ypos, config.trace_color[t]);
+      j++;
+    }
+  } else {
+    for (t = 0; t < TRACES_MAX; t++) {
+      if (!trace[t].enabled)
+        continue;
+      int xpos = 1 + (j%2)*146;
+      int ypos = 1 + (j/2)*7;
+      xpos -= m * CELLWIDTH -CELLOFFSETX;
+      ypos -= n * CELLHEIGHT;
+      strcpy(buf, "CH0");
+      buf[2] += t;
+      chsnprintf(buf, sizeof buf, "CH%d", trace[t].channel);
+      cell_drawstring_invert_5x7(w, h, buf, xpos, ypos, config.trace_color[t], t == uistat.current_trace);
+      xpos += 20;
+      trace_get_info(t, buf, sizeof buf);
+      cell_drawstring_5x7(w, h, buf, xpos, ypos, config.trace_color[t]);
+      xpos += 64;
+      trace_get_value_string(t, buf, sizeof buf, measured[trace[t].channel], idx);
+      cell_drawstring_5x7(w, h, buf, xpos, ypos, config.trace_color[t]);
+      j++;
+    }
+  }
   if (electrical_delay != 0) {
     // draw electrical delay
     int xpos = 21;
diff --git a/ui.c b/ui.c
index 91687fe..030a2b3 100644
--- a/ui.c
+++ b/ui.c
@@ -839,6 +839,8 @@ menu_marker_op_cb(int item)
     break;
   case 4: /* MARKERS->EDELAY */
     { 
+      if (uistat.current_trace == -1)
+        break;
       float (*array)[2] = measured[trace[uistat.current_trace].channel];
       float v = groupdelay_from_array(markers[active_marker].index, array);
       set_electrical_delay(electrical_delay + (v / 1e-12));