diff --git a/netbox/dcim/ui/panels.py b/netbox/dcim/ui/panels.py
index 87ceb9c4a..a47ae3d2b 100644
--- a/netbox/dcim/ui/panels.py
+++ b/netbox/dcim/ui/panels.py
@@ -31,7 +31,7 @@ class RackDimensionsPanel(panels.ObjectAttributesPanel):
     outer_width = attrs.NumericAttr('outer_width', unit_accessor='get_outer_unit_display')
     outer_height = attrs.NumericAttr('outer_height', unit_accessor='get_outer_unit_display')
     outer_depth = attrs.NumericAttr('outer_depth', unit_accessor='get_outer_unit_display')
-    mounting_depth = attrs.TextAttr('mounting_depth', format_string='{}mm')
+    mounting_depth = attrs.TextAttr('mounting_depth', format_string='{} mm')
 
 
 class RackNumberingPanel(panels.ObjectAttributesPanel):