diff --git a/src/material-examples/select-panel-class/select-panel-class-example.css b/src/material-examples/select-panel-class/select-panel-class-example.css
index 090739dbe91..5e9cac9d255 100644
--- a/src/material-examples/select-panel-class/select-panel-class-example.css
+++ b/src/material-examples/select-panel-class/select-panel-class-example.css
@@ -1,11 +1,11 @@
-.example-panel-red .mat-select-panel {
+.example-panel-red.mat-select-panel {
   background: rgba(255, 0, 0, 0.5);
 }
 
-.example-panel-green .mat-select-panel {
+.example-panel-green.mat-select-panel {
   background: rgba(0, 255, 0, 0.5);
 }
 
-.example-panel-blue .mat-select-panel {
+.example-panel-blue.mat-select-panel {
   background: rgba(0, 0, 255, 0.5);
 }