diff --git a/lasercut/join.py b/lasercut/join.py
index 3b9a12d..e73d06b 100644
--- a/lasercut/join.py
+++ b/lasercut/join.py
@@ -37,8 +37,8 @@ def get_slot_positions(tab_properties):
     if tab_properties.tabs_number % 2 == 1:
         slots_list.append(0.0 + tab_properties.tabs_shift)
         for i in range(half_tab_number):
-            left = float(i+1) * interval_length * tab_properties.interval_ratio
-            right = float(-i-1) * interval_length * tab_properties.interval_ratio
+            left = float(i+1) * interval_length
+            right = float(-i-1) * interval_length
             if tab_properties.interval_ratio != 1.0:
                 left *= tab_properties.interval_ratio
                 right *= tab_properties.interval_ratio
diff --git a/panel/tab.py b/panel/tab.py
index 892efbd..a86a568 100644
--- a/panel/tab.py
+++ b/panel/tab.py
@@ -48,7 +48,7 @@ def __init__(self, tab_properties):
                                 WidgetValue(type=float, name="tabs_shift", show_name="Shift", widget=None,
                                             interval_value=[-300, 300.], step=1., decimals=2),
                                 WidgetValue(type=float, name="interval_ratio", show_name="Interval ratio",
-                                            widget=None, interval_value=[0.1, 5.], step=0.1, decimals=2),
+                                            widget=None, interval_value=[0.1, 5.], step=0.1, decimals=3),
                                 WidgetValue(type=bool, name="dog_bone", show_name="Dog bone hole", widget=None),
                                 WidgetValue(type=bool, name="tab_dog_bone", show_name="Tab dog bone hole", widget=None)
                                  ])