diff --git src/wp-content/themes/twentynineteen/style-editor.css src/wp-content/themes/twentynineteen/style-editor.css
index 1e0bd69390..5381974d64 100644
--- src/wp-content/themes/twentynineteen/style-editor.css
+++ src/wp-content/themes/twentynineteen/style-editor.css
@@ -1239,6 +1239,11 @@ figcaption,
   margin-left: 0;
 }
 
+/* preformatted block font-size */
+.editor-styles-wrapper .wp-block-preformatted {
+  font-size: 0.75em;
+}
+
 /** === Verse === */
 .wp-block-verse,
 .wp-block-verse pre {
diff --git src/wp-content/themes/twentynineteen/style.css src/wp-content/themes/twentynineteen/style.css
index 42e966189a..e8490b975f 100644
--- src/wp-content/themes/twentynineteen/style.css
+++ src/wp-content/themes/twentynineteen/style.css
@@ -5654,9 +5654,10 @@ body.page .main-navigation {
 }
 
 .entry .entry-content .wp-block-preformatted {
-  font-size: 0.71111em;
+  font-size: 0.75em;
   line-height: 1.8;
   padding: 1rem;
+  font-family: monospace;
 }
 
 .entry .entry-content .wp-block-verse {