diff --git a/.changeset/mean-shrimps-train.md b/.changeset/mean-shrimps-train.md
new file mode 100644
index 0000000..1ede060
--- /dev/null
+++ b/.changeset/mean-shrimps-train.md
@@ -0,0 +1,5 @@
+---
+"eslint-plugin-primer-react": patch
+---
+
+Add null check to enforce-css-module-identifier-casing.js. Corrects complex instances where ref.resolve is not available.
diff --git a/src/rules/enforce-css-module-identifier-casing.js b/src/rules/enforce-css-module-identifier-casing.js
index fbefec6..e542740 100644
--- a/src/rules/enforce-css-module-identifier-casing.js
+++ b/src/rules/enforce-css-module-identifier-casing.js
@@ -57,7 +57,7 @@ module.exports = {
             const ref = context.sourceCode
               .getScope(node)
               .references.find(reference => reference.identifier.name === node.property.name)
-            const def = ref.resolved?.defs?.[0]
+            const def = ref?.resolved?.defs?.[0]
             if (def?.node?.init?.type === 'Literal') {
               if (!casingMatches(def.node.init.value || '', casing)) {
                 context.report({