diff --git a/js/gdm/loginDialog.js b/js/gdm/loginDialog.js
index 3700f0c44..46f3fa473 100644
--- a/js/gdm/loginDialog.js
+++ b/js/gdm/loginDialog.js
@@ -205,7 +205,8 @@ const UserListItem = new Lang.Class({
             // We use background-image instead of, say, St.TextureCache
             // so the theme writers can add a rounded frame around the image
             // and so theme writers can pick the icon size.
-            this._iconBin.set_style('background-image: url("' + iconFile + '");');
+            this._iconBin.set_style('background-image: url("' + iconFile + '");' +
+                                    'background-size: contain;');
         } else {
             this._iconBin.hide();
         }
diff --git a/js/ui/endSessionDialog.js b/js/ui/endSessionDialog.js
index d21d155cb..39cbcf870 100644
--- a/js/ui/endSessionDialog.js
+++ b/js/ui/endSessionDialog.js
@@ -333,7 +333,8 @@ const EndSessionDialog = new Lang.Class({
         this._iconBin.child = null;
         if (iconFile) {
             this._iconBin.show();
-            this._iconBin.set_style('background-image: url("' + iconFile + '");');
+            this._iconBin.set_style('background-image: url("' + iconFile + '");' +
+                                    'background-size: contain;');
         } else {
             this._iconBin.hide();
         }
diff --git a/js/ui/userMenu.js b/js/ui/userMenu.js
index fdac848f5..e1757e33a 100644
--- a/js/ui/userMenu.js
+++ b/js/ui/userMenu.js
@@ -239,7 +239,8 @@ const IMStatusChooserItem = new Lang.Class({
     },
 
     _setIconFromFile: function(iconFile) {
-        this._iconBin.set_style('background-image: url("' + iconFile + '");');
+        this._iconBin.set_style('background-image: url("' + iconFile + '");' +
+                                'background-size: contain;');
         this._iconBin.child = null;
     },