diff --git a/scss/_functions.scss b/scss/_functions.scss
index f8e43702d529..1f3263175e99 100644
--- a/scss/_functions.scss
+++ b/scss/_functions.scss
@@ -191,14 +191,6 @@ $_luminance-list: .0008 .001 .0011 .0013 .0015 .0017 .002 .0022 .0025 .0027 .003
     @return $value1 + $value2;
   }
 
-  @if type-of($value1) != number {
-    $value1: unquote("(") + $value1 + unquote(")");
-  }
-
-  @if type-of($value2) != number {
-    $value2: unquote("(") + $value2 + unquote(")");
-  }
-
   @return if($return-calc == true, calc(#{$value1} + #{$value2}), $value1 + unquote(" + ") + $value2);
 }
 
@@ -219,10 +211,6 @@ $_luminance-list: .0008 .001 .0011 .0013 .0015 .0017 .002 .0022 .0025 .0027 .003
     @return $value1 - $value2;
   }
 
-  @if type-of($value1) != number {
-    $value1: unquote("(") + $value1 + unquote(")");
-  }
-
   @if type-of($value2) != number {
     $value2: unquote("(") + $value2 + unquote(")");
   }