diff --git a/.changeset/quiet-lamps-smile.md b/.changeset/quiet-lamps-smile.md
new file mode 100644
index 0000000000..3eaf6f5ba4
--- /dev/null
+++ b/.changeset/quiet-lamps-smile.md
@@ -0,0 +1,5 @@
+---
+"@primer/css": patch
+---
+
+Make list type selector case sensitive
diff --git a/src/markdown/lists.scss b/src/markdown/lists.scss
index 6b342678a3..10a3a8648e 100644
--- a/src/markdown/lists.scss
+++ b/src/markdown/lists.scss
@@ -14,19 +14,19 @@
     }
   }
 
-  ol[type='a'] {
+  ol[type='a s'] {
     list-style-type: lower-alpha;
   }
 
-  ol[type='A'] {
+  ol[type='A s'] {
     list-style-type: upper-alpha;
   }
 
-  ol[type='i'] {
+  ol[type='i s'] {
     list-style-type: lower-roman;
   }
 
-  ol[type='I'] {
+  ol[type='I s'] {
     list-style-type: upper-roman;
   }