diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9e56063..d232585 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,7 +7,8 @@
 
 ### Added
 
-- Sensors associated with a selected logical block are now highlighted.
+- Improved reverse entry marker UX. User can remove the marker and cancel adding one (https://github.com/Novakasa/brickrail/issues/133).
+- Markers associated with a selected logical block are now highlighted.
 - Trains and Blocks can now be renamed by clicking their names in the inspector (https://github.com/Novakasa/brickrail/issues/122).
 - Added debug color buffer and plot written to file after unexpected Marker (https://github.com/Novakasa/brickrail/issues/144)
 - Spacebar now triggers emergency stop. For the extra urgent emergencies.
diff --git a/brickrail-gui/layout/block/layout_block_inspector.gd b/brickrail-gui/layout/block/layout_block_inspector.gd
index 7d5ec83..a1e1253 100644
--- a/brickrail-gui/layout/block/layout_block_inspector.gd
+++ b/brickrail-gui/layout/block/layout_block_inspector.gd
@@ -7,10 +7,12 @@ func _enter_tree():
 	var _err = LayoutInfo.connect("layout_mode_changed", self, "_on_layout_mode_changed")
 
 func _on_layout_mode_changed(mode):
-	var edit_exclusive_nodes = [$AddTrain, $AddPriorSensorButton, $CanStopCheckBox, $CanFlipCheckBox]
+	var edit_exclusive_nodes = [$AddTrain, $PriorPanel, $PriorLabel, $CanStopCheckBox, $CanFlipCheckBox]
 	
 	for node in edit_exclusive_nodes:
 		node.visible = (mode != "control")
+	
+	update_prior_panel()
 
 func set_block(p_block):
 	block = p_block
@@ -21,8 +23,24 @@ func set_block(p_block):
 	$CanFlipCheckBox.pressed = block.can_flip
 	$RandomTargetCheckBox.pressed = block.random_target
 	$HBoxContainer/WaitTimeEdit.value = block.wait_time
+	update_prior_panel()
 	_on_layout_mode_changed(LayoutInfo.layout_mode)
 
+func update_prior_panel():
+	if block.get_prior_sensor_dirtrack() == null:
+		if LayoutInfo.layout_mode == "prior_sensor":
+			$PriorPanel/AddPriorButton.disabled = true
+			$PriorPanel/RemovePriorButton.disabled = true
+			$PriorPanel/CancelPriorButton.disabled = false
+			return
+		$PriorPanel/AddPriorButton.disabled = false
+		$PriorPanel/RemovePriorButton.disabled = true
+		$PriorPanel/CancelPriorButton.disabled = true
+		return
+	$PriorPanel/AddPriorButton.disabled = true
+	$PriorPanel/RemovePriorButton.disabled = false
+	$PriorPanel/CancelPriorButton.disabled = true
+
 func _on_block_unselected():
 	queue_free()
 
@@ -37,10 +55,6 @@ func _on_AddTrainDialog_confirmed():
 	var train: LayoutTrain = LayoutInfo.create_train()
 	train.set_current_block(block)
 
-func _on_AddPriorSensorButton_pressed():
-	LayoutInfo.set_layout_mode("prior_sensor")
-
-
 func _on_CanStopCheckBox_toggled(button_pressed):
 	if block.can_stop != button_pressed:
 		LayoutInfo.set_layout_changed(true)
@@ -60,4 +74,15 @@ func _on_WaitTimeEdit_value_changed(value):
 func _on_EditableLabel_text_changed(text):
 	LayoutInfo.blocks[block.block_id].set_name(text)
 	$EditableLabel.set_display_text(block.get_name())
-	
+
+func _on_AddPriorSensorButton_pressed():
+	LayoutInfo.set_layout_mode("prior_sensor")
+	update_prior_panel()
+
+func _on_RemovePriorButton_pressed():
+	block.disconnect_prior_sensor_dirtrack()
+	update_prior_panel()
+
+func _on_CancelPriorButton_pressed():
+	LayoutInfo.set_layout_mode("edit")
+	update_prior_panel()
diff --git a/brickrail-gui/layout/block/layout_block_inspector.tscn b/brickrail-gui/layout/block/layout_block_inspector.tscn
index db2197b..faa87e9 100644
--- a/brickrail-gui/layout/block/layout_block_inspector.tscn
+++ b/brickrail-gui/layout/block/layout_block_inspector.tscn
@@ -9,23 +9,88 @@ margin_bottom = 40.0
 script = ExtResource( 1 )
 
 [node name="EditableLabel" type="VBoxContainer" parent="."]
-margin_right = 175.0
+margin_right = 183.0
 script = ExtResource( 2 )
 
 [node name="AddTrain" type="Button" parent="."]
 margin_top = 4.0
-margin_right = 175.0
+margin_right = 183.0
 margin_bottom = 24.0
 text = "Add train"
 __meta__ = {
 "_edit_use_anchors_": false
 }
 
-[node name="AddPriorSensorButton" type="Button" parent="."]
+[node name="PriorLabel" type="Label" parent="."]
 margin_top = 28.0
-margin_right = 175.0
-margin_bottom = 48.0
-text = "Add reverse entry marker"
+margin_right = 183.0
+margin_bottom = 42.0
+text = "Reverse Entry Marker"
+
+[node name="PriorPanel" type="HBoxContainer" parent="."]
+margin_top = 46.0
+margin_right = 183.0
+margin_bottom = 66.0
+
+[node name="AddPriorButton" type="Button" parent="PriorPanel"]
+margin_right = 37.0
+margin_bottom = 20.0
+text = "Add"
+
+[node name="RemovePriorButton" type="Button" parent="PriorPanel"]
+margin_left = 41.0
+margin_right = 125.0
+margin_bottom = 20.0
+text = "Disconnect"
+
+[node name="CancelPriorButton" type="Button" parent="PriorPanel"]
+margin_left = 129.0
+margin_right = 183.0
+margin_bottom = 20.0
+text = "Cancel"
+
+[node name="ControlLabel" type="Label" parent="."]
+margin_top = 70.0
+margin_right = 183.0
+margin_bottom = 84.0
+text = "Train control"
+
+[node name="CanStopCheckBox" type="CheckBox" parent="."]
+margin_top = 88.0
+margin_right = 183.0
+margin_bottom = 112.0
+pressed = true
+text = "Can stop"
+
+[node name="CanFlipCheckBox" type="CheckBox" parent="."]
+margin_top = 116.0
+margin_right = 183.0
+margin_bottom = 140.0
+pressed = true
+text = "Can reverse"
+
+[node name="RandomTargetCheckBox" type="CheckBox" parent="."]
+margin_top = 144.0
+margin_right = 183.0
+margin_bottom = 168.0
+text = "Random target"
+
+[node name="HBoxContainer" type="HBoxContainer" parent="."]
+margin_top = 172.0
+margin_right = 183.0
+margin_bottom = 196.0
+
+[node name="Label" type="Label" parent="HBoxContainer"]
+margin_top = 5.0
+margin_right = 82.0
+margin_bottom = 19.0
+text = "Wait time [s]"
+
+[node name="WaitTimeEdit" type="SpinBox" parent="HBoxContainer"]
+margin_left = 86.0
+margin_right = 160.0
+margin_bottom = 24.0
+max_value = 100000.0
 
 [node name="AddTrainDialog" type="ConfirmationDialog" parent="."]
 margin_top = 42.0
@@ -65,48 +130,13 @@ __meta__ = {
 "_edit_use_anchors_": false
 }
 
-[node name="CanStopCheckBox" type="CheckBox" parent="."]
-margin_top = 52.0
-margin_right = 175.0
-margin_bottom = 76.0
-pressed = true
-text = "Can stop"
-
-[node name="CanFlipCheckBox" type="CheckBox" parent="."]
-margin_top = 80.0
-margin_right = 175.0
-margin_bottom = 104.0
-pressed = true
-text = "Can reverse"
-
-[node name="RandomTargetCheckBox" type="CheckBox" parent="."]
-margin_top = 108.0
-margin_right = 175.0
-margin_bottom = 132.0
-text = "Random target"
-
-[node name="HBoxContainer" type="HBoxContainer" parent="."]
-margin_top = 136.0
-margin_right = 175.0
-margin_bottom = 160.0
-
-[node name="Label" type="Label" parent="HBoxContainer"]
-margin_top = 5.0
-margin_right = 82.0
-margin_bottom = 19.0
-text = "Wait time [s]"
-
-[node name="WaitTimeEdit" type="SpinBox" parent="HBoxContainer"]
-margin_left = 86.0
-margin_right = 160.0
-margin_bottom = 24.0
-max_value = 100000.0
-
 [connection signal="text_changed" from="EditableLabel" to="." method="_on_EditableLabel_text_changed"]
 [connection signal="pressed" from="AddTrain" to="." method="_on_AddTrain_pressed"]
-[connection signal="pressed" from="AddPriorSensorButton" to="." method="_on_AddPriorSensorButton_pressed"]
-[connection signal="confirmed" from="AddTrainDialog" to="." method="_on_AddTrainDialog_confirmed"]
+[connection signal="pressed" from="PriorPanel/AddPriorButton" to="." method="_on_AddPriorSensorButton_pressed"]
+[connection signal="pressed" from="PriorPanel/RemovePriorButton" to="." method="_on_RemovePriorButton_pressed"]
+[connection signal="pressed" from="PriorPanel/CancelPriorButton" to="." method="_on_CancelPriorButton_pressed"]
 [connection signal="toggled" from="CanStopCheckBox" to="." method="_on_CanStopCheckBox_toggled"]
 [connection signal="toggled" from="CanFlipCheckBox" to="." method="_on_CanFlipCheckBox_toggled"]
 [connection signal="toggled" from="RandomTargetCheckBox" to="." method="_on_RandomTargetCheckBox_toggled"]
 [connection signal="value_changed" from="HBoxContainer/WaitTimeEdit" to="." method="_on_WaitTimeEdit_value_changed"]
+[connection signal="confirmed" from="AddTrainDialog" to="." method="_on_AddTrainDialog_confirmed"]
diff --git a/brickrail-gui/layout/block/layout_logical_block.gd b/brickrail-gui/layout/block/layout_logical_block.gd
index 45a27d8..6987d4b 100644
--- a/brickrail-gui/layout/block/layout_logical_block.gd
+++ b/brickrail-gui/layout/block/layout_logical_block.gd
@@ -65,6 +65,12 @@ func add_prior_sensor_dirtrack(dirtrack):
 		dirtrack.get_sensor().increment_highlight(1)
 	LayoutInfo.set_layout_changed(true)
 
+func disconnect_prior_sensor_dirtrack():
+	assert(get_prior_sensor_dirtrack() != null)
+	if selected:
+		nodes[-1].sensors.sensor_dirtracks["enter"].get_sensor().increment_highlight(-1)
+	nodes[-1].sensors.set_sensor_dirtrack("enter", null)
+
 func get_prior_sensor_dirtrack():
 	return nodes[-1].sensors.sensor_dirtracks["enter"]