diff --git a/src/cdk/overlay/_index.scss b/src/cdk/overlay/_index.scss
index ce8be7b73c5b..8b351bfca653 100644
--- a/src/cdk/overlay/_index.scss
+++ b/src/cdk/overlay/_index.scss
@@ -85,7 +85,6 @@ $backdrop-animation-timing-function: cubic-bezier(0.25, 0.8, 0.25, 1) !default;
   }
 
   .cdk-overlay-backdrop {
-    // TODO(jelbourn): reuse sidenav fullscreen mixin.
     position: absolute;
     top: 0;
     bottom: 0;
@@ -100,6 +99,10 @@ $backdrop-animation-timing-function: cubic-bezier(0.25, 0.8, 0.25, 1) !default;
       z-index: $overlay-backdrop-z-index;
       transition: opacity $backdrop-animation-duration $backdrop-animation-timing-function;
     }
+
+    @media (prefers-reduced-motion) {
+      transition-duration: 1ms;
+    }
   }
 
   .cdk-overlay-backdrop-showing {