diff --git a/.changeset/nine-taxis-study.md b/.changeset/nine-taxis-study.md
new file mode 100644
index 0000000000..693534c2be
--- /dev/null
+++ b/.changeset/nine-taxis-study.md
@@ -0,0 +1,5 @@
+---
+'@backstage/core-components': patch
+---
+
+Minor internal tweak to handle `classnames` update
diff --git a/packages/core-components/src/layout/Sidebar/Items.tsx b/packages/core-components/src/layout/Sidebar/Items.tsx
index 715e0d4af7..c40d45f8b4 100644
--- a/packages/core-components/src/layout/Sidebar/Items.tsx
+++ b/packages/core-components/src/layout/Sidebar/Items.tsx
@@ -351,7 +351,7 @@ export const WorkaroundNavLink = React.forwardRef<
       aria-current={ariaCurrent}
       style={{ ...style, ...(isActive ? activeStyle : undefined) }}
       className={classnames([
-        className,
+        typeof className !== 'function' ? className : undefined,
         isActive ? activeClassName : undefined,
       ])}
     />
diff --git a/yarn.lock b/yarn.lock
index cd1f6d752c..78d55e945d 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -21802,9 +21802,9 @@ __metadata:
   linkType: hard
 
 "classnames@npm:*, classnames@npm:^2.2.5, classnames@npm:^2.2.6, classnames@npm:^2.3.1":
-  version: 2.3.1
-  resolution: "classnames@npm:2.3.1"
-  checksum: 14db8889d56c267a591f08b0834989fe542d47fac659af5a539e110cc4266694e8de86e4e3bbd271157dbd831361310a8293e0167141e80b0f03a0f175c80960
+  version: 2.3.2
+  resolution: "classnames@npm:2.3.2"
+  checksum: 2c62199789618d95545c872787137262e741f9db13328e216b093eea91c85ef2bfb152c1f9e63027204e2559a006a92eb74147d46c800a9f96297ae1d9f96f4e
   languageName: node
   linkType: hard