diff --git a/modules/primer-forms/lib/form-control.scss b/modules/primer-forms/lib/form-control.scss
index f8f88f5b..fdcce96f 100644
--- a/modules/primer-forms/lib/form-control.scss
+++ b/modules/primer-forms/lib/form-control.scss
@@ -63,7 +63,7 @@ label {
 // Large inputs
 .input-lg {
   padding: 4px 10px;
-  font-size: 16px;
+  font-size: $h4-size;
 }
 
 // Full-width inputs
diff --git a/modules/primer-markdown/lib/markdown-body.scss b/modules/primer-markdown/lib/markdown-body.scss
index bb462772..a758ad93 100644
--- a/modules/primer-markdown/lib/markdown-body.scss
+++ b/modules/primer-markdown/lib/markdown-body.scss
@@ -7,7 +7,7 @@ $margin: 16px;
 // includes some GitHub Flavored Markdown specific styling (like @mentions)
 .markdown-body {
   font-family: $body-font;
-  font-size: 16px;
+  font-size: $h4-size;
   line-height: $body-line-height;
   word-wrap: break-word;
 
diff --git a/modules/primer-marketing-type/lib/typography.scss b/modules/primer-marketing-type/lib/typography.scss
index 82ff47ec..9724b2a8 100644
--- a/modules/primer-marketing-type/lib/typography.scss
+++ b/modules/primer-marketing-type/lib/typography.scss
@@ -64,7 +64,7 @@
 }
 
 .alt-h4 {
-  font-size: 16px;
+  font-size: $h4-size;
   font-weight: $font-weight-semibold;
 }