diff --git a/components/style/media_queries/media_feature_expression.rs b/components/style/media_queries/media_feature_expression.rs
index 1eef9e57ebc5..d4124450dc5e 100644
--- a/components/style/media_queries/media_feature_expression.rs
+++ b/components/style/media_queries/media_feature_expression.rs
@@ -36,7 +36,7 @@ impl ToCss for AspectRatio {
         W: fmt::Write,
     {
         self.0.to_css(dest)?;
-        dest.write_char('/')?;
+        dest.write_str(" / ")?;
         self.1.to_css(dest)
     }
 }
diff --git a/components/style/properties/shorthands/font.mako.rs b/components/style/properties/shorthands/font.mako.rs
index b64268226663..e3b44d86a36b 100644
--- a/components/style/properties/shorthands/font.mako.rs
+++ b/components/style/properties/shorthands/font.mako.rs
@@ -221,7 +221,7 @@
             self.font_size.to_css(dest)?;
 
             if *self.line_height != LineHeight::normal() {
-                dest.write_str("/")?;
+                dest.write_str(" / ")?;
                 self.line_height.to_css(dest)?;
             }