diff --git a/components/brave_account/endpoint_client/client_unittest.cc b/components/brave_account/endpoint_client/client_unittest.cc
index 5a769c1d5c3..9b4caee73ec 100644
--- a/components/brave_account/endpoint_client/client_unittest.cc
+++ b/components/brave_account/endpoint_client/client_unittest.cc
@@ -87,7 +87,7 @@ bool operator==(const JSONErrorBody& lhs, const JSONErrorBody& rhs) {
   return lhs.error == rhs.error;
 }
 
-bool operator==(const JSONEmptyBody&, const JSONEmptyBody&) {
+inline bool operator==(const JSONEmptyBody&, const JSONEmptyBody&) {
   return true;
 }