diff --git a/modules/ui/fields/restrictions.js b/modules/ui/fields/restrictions.js
index eb377eb10..c0104a4d8 100644
--- a/modules/ui/fields/restrictions.js
+++ b/modules/ui/fields/restrictions.js
@@ -235,7 +235,14 @@ export function uiFieldRestrictions(field, context) {
         var filter = utilFunctor(true);
         var projection = geoRawMercator();
 
-        var d = utilGetDimensions(selection);
+        // Reflow warning: `utilGetDimensions` calls `getBoundingClientRect`
+        // Instead of asking the restriction-container for its dimensions,
+        //  we can ask the #sidebar, which can have its dimensions cached.
+        // width: calc as sidebar - padding
+        // height: hardcoded (from `80_app.css`)
+        // var d = utilGetDimensions(selection);
+        var sdims = utilGetDimensions(d3_select('#sidebar'));
+        var d = [ sdims[0] - 50, 370 ];
         var c = geoVecScale(d, 0.5);
         var z = 22;
 
diff --git a/modules/ui/init.js b/modules/ui/init.js
index 48977559f..497201b0a 100644
--- a/modules/ui/init.js
+++ b/modules/ui/init.js
@@ -390,8 +390,12 @@ export function uiInit(context) {
 
     ui.onResize = function(withPan) {
         var map = context.map();
-        var content = d3_select('#content');
-        var mapDimensions = utilGetDimensions(content, true);
+
+        // Recalc dimensions of map and sidebar.. (`true` = force recalc)
+        // This will call `getBoundingClientRect` and trigger reflow,
+        //  but the values will be cached for later use.
+        var mapDimensions = utilGetDimensions(d3_select('#content'), true);
+        utilGetDimensions(d3_select('#sidebar'), true);
 
         if (withPan !== undefined) {
             map.redrawEnable(false);