diff --git a/src/lib/core/option/_option-theme.scss b/src/lib/core/option/_option-theme.scss
index 6a2a0fdb2587..a8eae7868705 100644
--- a/src/lib/core/option/_option-theme.scss
+++ b/src/lib/core/option/_option-theme.scss
@@ -30,7 +30,7 @@
 
     // In multiple mode there is a checkbox to show that the option is selected.
     &.mat-selected:not(.mat-option-multiple) {
-      background: mat-color($background, hover);
+      background: rgba(mat-color($background, hover), 0.12);
     }
 
     &.mat-active {