diff --git a/src/material-experimental/mdc-helpers/_mdc-helpers.scss b/src/material-experimental/mdc-helpers/_mdc-helpers.scss
index 10a107b0654e..7d2cfa75be61 100644
--- a/src/material-experimental/mdc-helpers/_mdc-helpers.scss
+++ b/src/material-experimental/mdc-helpers/_mdc-helpers.scss
@@ -96,11 +96,12 @@ $mat-typography-2018-level-mappings: (
       $mat-typography-2018-level-mappings, $mat-typography-2014-level-mappings);
   $mdc-level: map-get(map-get($mappings, mat-to-mdc), $mat-level);
 
-  $result-with-nulls: map-merge(
+  @return map-merge(
       if($mdc-level,
           map-get($mdc-typography-styles, $mdc-level),
           (
             text-decoration: none,
+            text-transform: none,
             -moz-osx-font-smoothing: grayscale,
             -webkit-font-smoothing: antialiased
           )),
@@ -112,19 +113,9 @@ $mat-typography-2018-level-mappings: (
             letter-spacing: mat-letter-spacing($mat-config, $mat-level),
             font-family: mat-font-family($mat-config, $mat-level),
             // Angular Material doesn't use text-transform, so disable it.
-            text-transform: null,
+            text-transform: none,
           ),
           ()));
-
-  // We need to strip out any keys with a null value. Leaving them in will cause MDC to emit CSS
-  // variables with no fallback value, which breaks some builds.
-  $result: ();
-  @each $property, $value in $result-with-nulls {
-    @if $value != null {
-      $result: map-merge($result, ($property: $value));
-    }
-  }
-  @return $result;
 }
 
 // Converts an Angular Material typography config to an MDC one.